diff --git a/2020/inputs/18.txt b/2020/inputs/18.txt
new file mode 100644
index 0000000..bddf958
--- /dev/null
+++ b/2020/inputs/18.txt
@@ -0,0 +1,373 @@
+9 + (9 * 5 + 8 * 8 + 6) * 8
+8 + (4 + 7) + 6 + ((5 * 4) * (5 * 7) * (3 + 7 * 4 + 5 * 7) * 4) + 4 * 8
+3 * 4 * (6 * 4) + 5 * 3 + 6
+7 * 6 + ((8 + 6 * 6 + 2 + 3) + 9 * (2 * 4 * 8 * 4)) + 8 * 6 + 9
+(7 + 8) * 8 + 5
+4 * 2 * 6 * (8 * 7 * (7 * 9 * 6) + 8) + 3
+3 * 8 * 9 + (5 + (5 + 2) + 5 + (5 + 5 + 8) * 5) + 6
+(2 + 7 + (6 + 8 + 8 + 6 * 4) + 4 + 3) + 2 + (4 * 3 + 2) + (6 * 4) * 8 + 3
+3 * 8 * 4 + ((6 + 6 + 5) * 6 * 9 + (3 + 6 + 9 + 3 + 4 + 6)) + 7
+6 * 2 + (8 * 9 * (8 * 9 * 2 * 5) + (4 + 8) * 2 + 8) + 9
+9 + (7 + (4 + 7 * 5)) * 3 + 8 * 3 + 5
+9 * 5 + (5 * 3 + 4 * 3) + 2 * 5
+7 * (3 * 9 * 5) + 7 * 3 * 7 * 6
+8 * (7 * 6 * 6) + (3 * 6) + 3 * 3
+(9 + 8 + 5) * 8 + 7 * 9
+6 + 3 * (5 + 3) + 3 + 6 * (9 * 5 + 7 + 3 + (5 * 9 * 3 * 5 + 3) * 4)
+(4 * 5 + 7) * 6
+5 * 8 * 8 * (5 + 6)
+4 + 9 * (3 + 3 + 2 * 4 + 8) * 2
+(5 * (3 * 4 * 9 + 2 * 7 * 3) + 8) * 3 * 7
+(9 + (5 + 2 + 8 * 9) + (5 + 5)) + 5 + 2 + 5 + 8 + 5
+9 * 6 * 2 * ((4 + 7 * 6 + 7 * 3 + 9) * 4 + 5 * 8) * 2 + 5
+(6 + 5 + (8 + 3 * 3 * 5 * 3)) * 2 * 7 * 2
+7 * 4 + 3 * 2 + 2 * (4 + (4 * 4 * 6 * 8) * 2 + (4 * 3 * 7 * 8) * 2 + 9)
+8 * 3 * 3 + 7 + 8 * (9 * 3 * 7 * 9 + (7 + 8))
+(4 * 3) + 4 * 3 * 2 * 6
+(7 + 9 + 6 + 8 + (3 + 8 + 7 * 8 * 7)) * 3 * (6 * 3 + 5 + 6 * (4 + 8 + 5 + 2) + (7 + 7 * 7 * 3)) + ((6 * 3 * 6 * 7 * 7 * 2) * 3 + 6 * 3) + 9 * (2 + 4 * 2)
+((7 * 2 * 4) + 4 * 2 + 3 + 3) * 7 * 4
+2 + 9 * 8 * 5 + 5 * 2
+3 * 7 * 5 + 7 + (4 + (6 * 7 + 5 * 2 + 4 + 5) * (2 * 2 * 3) * 2 + 8 + 5) * (3 + 6 + (9 + 2) * 6)
+7 + ((6 * 2) * 7 * 2 + 2 * 4 + 5) + 5 * 3 + 4
+2 + 7 * (6 * 3) + 8 * 6
+6 + 7 * 5 + (7 + (7 * 9 * 7 + 2) * 9 + 5 * 9 + 4)
+6 * 7 + ((5 + 6 * 2 * 9) * 9)
+9 + 5 + 2 + 6 + 5 + (7 + 8 + 8)
+7 + 8 + 2 * (8 * (7 + 2 + 8 + 6) * 6 * 3 + (3 * 9 * 7 * 9 + 4) * (9 + 6 + 4 * 7 * 6)) + (3 * (6 + 5 * 5))
+(2 + 8 + 5 + 2 + 7 * 5) * 5 + (2 * 5 * 8 * (3 * 5 * 9)) + 5 * 5 * (9 + 3 * 4 + (4 + 8 + 8 + 5 * 6 * 6) * (8 + 2 + 9 * 3))
+9 + (6 * (4 * 9 + 5) * 9 + (3 * 7 + 3 * 8) * 8 * 9)
+8 + 4 + (2 + 9 * 7 * 5)
+7 * (5 + 5) * (8 + (4 * 3 * 3 * 4 + 5 + 8) + 9) + 9 * 3 * 3
+7 * 7 * ((4 * 3) * 3 * 5 + 6 + 8) + (8 + 9 * (2 + 7 * 3 * 6 * 7 * 9) * 8)
+3 * (7 * (5 * 8 + 4)) * 5 + (9 + 9 * 5 + 8 + (6 * 4 + 2 * 2)) + 9
+(8 * (4 * 3 + 5) * 7 * 2) * (4 + 5 * 2 * 6 + 4) * 3 * 6
+(9 * (6 + 6 * 2 * 6 * 3 * 9)) + 8 + (3 * 6 * 7) + 4 + 8 + 4
+5 + 5 + 4 * 9 + ((6 * 9 * 6 * 2 * 4) + 9)
+9 + (7 + 2 + 3 + 8 * 4 + 3) + (5 * 9) + 9 * (6 * 8 * 7 * (4 * 9 * 6))
+(4 + 3) * (5 * 5 + 3 + 7 + 8) * 3 + 6 + 8 * 6
+4 * 8 + 5 * 6 + 4
+9 * 6 + 6 * 9
+9 + (2 * (4 * 9) + 3 + 4 + (7 + 5 + 2 * 6 * 8) * 7) * (3 * 5 + 8 * 4 + (3 * 7)) + 7 * (8 + 4)
+5 * ((4 * 7 * 3 * 6 + 5 + 8) + 2 * 4) * (4 + (5 * 2) * 3 + 8 + 3 + 3) + (6 + (6 + 2 * 6 + 6) + (6 * 8 * 2 * 9))
+(2 + (8 * 5 + 7 + 5 + 9) * 9 * 7) * ((3 + 4 * 8 * 3 * 8) + 3 * 6) + 3 + 2 + 7 * 8
+7 + 7 * 3 * ((8 + 3 + 4) + 7 * (6 + 5 * 8 + 3 * 3 * 3) * (5 * 9 + 9 * 8 * 9) + 7 + 5)
+7 + ((2 * 4 * 8 + 5) + 3 * (2 * 7 * 4 * 5) * (2 * 9 + 2) * 9 * 2) * 3
+2 * 5 + (4 * (5 + 7 * 7 + 3) * 9 * 7 * (8 + 9 + 3 + 2) + (7 + 7 * 9 * 7))
+8 * (6 * 7 * 7 * 3 + (7 + 2 + 2 + 3 + 7))
+4 + 7 * (6 * 7) * 5 * 9 + (7 * (4 * 2 + 2 + 8 * 2))
+6 * ((4 + 5 + 6 * 7 * 3) * 7 * 7 * 3) + 9 + 7
+3 * (7 * (6 * 7 + 3) + 3 * 4 * (7 * 4 + 2 * 4 + 4 * 8)) * ((5 * 9 + 7 + 9 * 3) * 3) + 2
+8 + 9 + 7 + 8 + 5 * (4 * 4 * 2 + 6 + 9)
+9 * (8 + 3 + 9 + (6 + 7 + 9) * 5) * ((8 * 8) * (6 * 6 * 5 * 9 + 7) * 6 * 7) + 5 + (9 * 7 + 8) + 9
+8 * 4 * 5 * 5 + 4 + 5
+2 * 3 + 6 + ((3 * 6 * 8) * 7) + 3
+(8 * 9 * 7) + 8 * (4 + (4 * 3 * 6 + 2) * 6) * 6
+4 + 7 + (8 + (7 + 9 * 6) * 3 * 8) + 7 * 5 + 7
+7 * 8 + (8 * 3) * 5 * (4 * 9 + 5 * 4 * 5 * 9)
+3 * (5 * (7 + 4 + 5 * 3 * 7) + 8 * 8 + 2)
+9 + (2 * (7 * 3 * 6 * 5 * 7) * 3 * 6 + 9 * (8 + 8 + 3 * 4 + 4 * 3))
+(6 * 7 * 2 * (2 * 9) + (2 + 3 + 7 * 4 + 6 + 7)) + 4 + 7 * (5 * 5 * 3 * 8 * 2 + (8 * 2 * 9))
+8 + 5 + 6 + 7 * (3 + 5 + 9 + (8 + 5) * 2)
+4 * 7 * (6 * 9 * 9 * 9) * (3 * (5 + 2 * 5) + 4 + 5 * 6 * 3) * 8
+(9 + 8 * 3 + 5 + (7 * 3 + 5 * 7 * 9 + 5) * 6) * 4
+((5 * 5 * 6 + 7) * 3 + 9) * 7
+(9 + 9) + 7 + 9 + 3 + (7 + 2 + 3 * (5 * 3 * 8 * 4 * 2)) + 6
+6 * 4 * 5 + 5 * 6
+9 + (9 + 3) + 5 + 8 * (7 * 9) * 9
+6 + (4 * 9 + (2 + 3 + 6 * 5 * 8 + 9) * (4 + 3 + 6 + 3 + 9 * 2) * 5) * 5 * 7 + 4 * 9
+7 * 7 + 6 + 5 * 6 * ((3 + 3 + 7) * 2)
+8 + (8 + 6 + 5 + 2 * (2 + 4 + 6 * 2 + 2)) * (4 * (3 + 7 * 2 + 4 * 7) + 4) + 5 + 3
+8 + 9 * 5 + 8 + (7 + 7 + 3 * 7 * 5 * 3) + 4
+(3 + 6 + 2 * 4 + 2) + 4 + 3
+7 * 9 * (5 + 7 * 6) * 9 + 7 * 9
+(8 * 8 * 5) + 5 * 6 * 4 * ((3 * 9 + 7 * 6 + 9) + 5 + 4)
+5 + 5 * 3 + ((2 * 5 * 3 * 6 + 5) + (5 * 9 * 2) * 9 + 5 * 8 * 2) * 6 + (2 * 9 * 5)
+4 * (3 + 7)
+3 + 2 * 5 + 2 + (9 + 8 * 7 * 4 + 4)
+3 + 7 * 9 * 5
+(5 + 4) + 3 * (7 * (3 * 8) * 3)
+3 * (9 * 5 + 5) * 5 + 4 + ((9 + 9 + 5 + 7) + 3 * 2 + 5) * ((6 + 9 + 3 * 6) * 4)
+7 * 6 * 4 + (2 * (7 * 5)) + (3 + (6 * 4 + 9 * 6 * 6 + 3) + 6 + 5) + 2
+3 * 7 * (8 + 7 + (5 + 8 + 5) + 3 + 3 * (6 + 7 + 4 * 8)) + 8
+7 * ((7 * 2 + 7) * (6 + 5 + 9 + 8 * 3)) + 3 * 9 * 2
+6 * 4 * 5 * 5 * 5 + ((7 * 3 * 5 * 4 + 4 + 8) * 3 * 5)
+8 * (3 + 3 * 8) + (7 * 2 * 7)
+(9 + 8 * 2) + 7 * (6 + 2 * 4 + 4 * 5 + (2 * 3)) + (4 + 4 + 2)
+5 * 7 + 9
+5 * (2 + 4 + (9 * 8 * 8 * 5) * 2) + 2 * 8 + ((6 + 5 + 3 + 6) + (6 * 4 * 8 * 8 * 7 + 9) * 5 + 5 + (9 + 8 * 9 * 2 + 6 * 3) * (8 + 4 * 2))
+7 + 9 + 7 * 9 + 7 * 5
+5 * ((9 + 5 + 6 + 6 * 9 + 8) * 9) + 8
+6 + 2 * (6 * (2 * 8 + 4 * 2 + 6 * 7) * 6 + (5 + 5 * 8 + 8)) + 3 + 3 * (2 * 2)
+6 * (7 * 5 * (2 + 4 * 7 * 8 * 9 * 4) * (6 * 4)) * (5 * 9 + (9 + 2 * 2) * 8 + 8) + 5 + 6 + 4
+8 + 4 + (7 * 4 * 6) + (7 + 8 + 7 + 2) + 7 + 4
+5 * 8 + 5 + (4 + 5 + 8 + 3 * (9 * 4 * 5))
+(6 * 4 + 9 + 7 * 9) * ((5 + 8 * 5 * 8) + 9 + 8 + 5)
+5 + 2 * 5 * (7 * (4 * 4 + 8) * (9 + 5 + 5 * 7) * 8 + 3 * 3) * 4 + 2
+4 * 2 + 5 + ((7 + 7 + 9 + 4 + 7 + 2) + (6 * 9 + 5 + 8 + 3) * 3 + 8 + 7) * 2
+9 + 2 * 2 + (5 + (8 * 4 + 3 * 3 * 3) + 9 + 4 + 4) * 6
+(7 + 2 + (4 * 5 * 3 + 6 + 6) + 4 + 6 * 6) + 2 + 4 + (2 + 6 + 2) + 9
+8 + 2 + 6 * (3 + 6 + 8 + 9 + (4 + 3 * 8 + 3 + 5) + (7 * 4 + 9 + 4 + 9 * 2)) * 5 + 2
+(8 + 6) + 2 + (5 + 8 + 3 * 2 * 4) + 7 + 5
+9 + 8 * (5 + 5) * 5 * 4 + (7 + 3 * 4 + (9 * 7 * 5 * 7) * (3 * 6 * 6 * 2))
+2 + 5 * 3 * (8 + 4 * 3 + 7 + 8 + 8)
+9 * 2 * 9 + ((7 + 4) * 2 + 9 + (2 * 7 * 3 + 3 + 5))
+(5 + 8 + 2 * 4) * (6 * 2 * 2 + 6 + (2 + 8) * 2) + (3 * 6 * 4) + 2 * 6 * (7 + 7 * (3 + 4 + 6) * 8 + 7 * 5)
+((7 + 7) + 7 + 7 + 4) + 4 * 5 * 2 * 8
+2 * 9 + (6 + 2 * 8 + 5 * 7)
+3 + 3 + 3 * 4 * (8 + 4 + 3 + 7) * 8
+((8 * 5 * 5) * 2 + 3 + 4 * 8 + 8) + 4 * 8 * 2
+(3 * (7 + 8 + 5 + 4 + 2 + 3) + 2 + 4) * 9 + 3
+3 + 3 + 2 + (8 + 7 + 6) + 5 + 7
+3 * 8 + 9 * ((7 + 6 * 5 * 5 + 2) * (4 * 8 * 9 + 3 + 7 + 7) * 9 * 3 * 4) + (3 * 8 * 7 * 9 + 5 * 5)
+(4 * 3 * 3 + 6 + 4 + 3) + 2 + (9 * 5 * (3 * 7 * 7 + 2)) + 8
+2 + (2 * (2 + 3 + 9) * (5 * 4 * 9 + 2 * 3) * (4 * 8 * 5 * 4) * (7 + 2 + 6)) * 8 + 8 * 5
+(7 * 7 + 9 * (3 + 5)) * 5 * 3 * 9 * 2
+9 + 3 * 6 + 9 + 3
+(5 + 2 * (9 * 7 * 6 + 6 * 7 * 7) + 2 * 6) * 7 + 6 + (4 + 4)
+(9 + 4 * 6 * 7 * 5 * 6) + 9
+3 * 8 + (7 + 3 + 3 + 3 + 7) * 6 * 8
+3 + 7 * (9 * 5 + (2 + 4 + 2 + 3 * 7) + 8 + (5 + 9)) + (7 * (7 + 7)) + (8 * 9)
+6 * (6 + 7 + 3 + 4) + 3 * 7 + 6 * 9
+(5 + 2 + 4) * 2 * 6 * 3 + (8 + 2 * 9) * 6
+4 * 4 * 4 * 7 + 6 + (6 * 7 * 7 + 9)
+3 * (5 * 7 * 9 + 6 * 9 * 9)
+8 * 5 * 7 + 4 * ((9 * 5) * 2) + 8
+7 * (7 * 5 * (3 * 4 + 2 + 5) + 6 * 3) * (5 * 9 * 8 + 5)
+8 + 4 * 7 + 4 + 7 * 6
+6 * 2 + (5 * (8 + 5 * 6 + 8) * (9 * 3 * 8 * 9 * 8 * 4) * 6 * 5)
+8 + 6 + (3 + 9 * 6 * 9 + 6 * 3) + 9 * 7
+6 + 7 + (8 + 4 * 2 + (3 * 9 * 7 * 7 * 8) * 2 + (8 + 2 * 8)) * 3 + 7
+7 + 3 + (6 * 4 * 3 * (4 + 7 * 7 + 7 * 6) + 5) + 4
+(2 + (4 * 9)) + 4 + 8 * 2 + 3
+6 * 7 * (2 * 5 + (8 + 2 + 4 * 2) + (9 * 4 * 7 + 3) * 6)
+6 + (8 + 4 * 4)
+5 * 8
+8 + (4 + 4 * 4 * 8) * 6 * 5 * 7
+3 + (6 * 4 + 8) + 4 * 5 * 2
+7 + (2 + 2 * 6 + 2) * 9 + (8 * 2 * 5) + 8
+5 + ((8 + 2 * 5) * 9 * 6 + 6) * 9
+4 + (6 * 9 * 7 + 7) + 8 + 6
+4 * (5 + 9 + (4 + 5 + 5 * 8) * (7 + 6 + 9 * 6 * 2) * 2) + 7 + 2 + (8 + 6 + 7 + 9 * 2) * 6
+(8 * 3) * 9 * (8 * 3 + 7 * 4 * (5 + 8 * 7 + 3) * 7)
+(3 + (8 + 3 * 9 + 3 * 6) * 4 * 2 * 2) + ((2 + 8 * 6 + 6) + 6 + 9 * 8 * 9) * 7 * 2 + 4 + 6
+3 + (7 * 2) + 2 * 9 + 6
+(7 * 7 + 9) * 9 * (2 + 6 * 9 * 2 * (8 * 2) * 3)
+2 + (8 * 2 + (8 + 7 * 3 + 2 * 8) * 3) + 4 + 3
+7 + ((9 + 3 + 4 * 8) + 9 + 3 + 8) * 3
+((7 + 3 + 8 * 5 * 3 + 2) * 5) * 5
+2 + 8 * (2 * 2 + 3 + 9) * (2 * 6 + 8) * 5 * (7 * 7 * 9 * 6 * 9)
+4 + 4 * (6 * 6 + (4 * 3 + 5) * 7) + 4 * 8 + 5
+9 + 4 + 2 + (2 * 4 + 4 * 8) * 6
+8 * 4 * 3 * (3 + 3 + 7) + 7
+3 * 8 + 8 + (3 + 6 + 9 + (4 * 5) * 5 + 9)
+(3 + 9 * 3) * 4 * 6
+4 + (7 * 6 + 2 * 6 + 9 + 2) * ((9 + 9 + 3 * 5 + 4) * 6 * 9) * ((4 * 5 * 9) + (7 * 8 * 7 * 8 * 8) * 8 + 3 * 4 * 6)
+8 + (3 + (9 + 7 * 9 + 4 + 4 + 7) * 4 * 6 * 8) * ((5 * 6 * 5) * 8 + 8 + 7 + 8 * (6 + 8 * 8 + 3)) + 7
+8 * 4 + ((4 + 3 * 6 + 9 + 9 + 8) + 2)
+7 + 8 + (6 * 5 + (9 * 4 * 2 * 7 * 6))
+8 + 3 * 9 * (8 * 5 * 3 + 6 + 6 * 7) * 4
+(5 + 7) + (4 * 3 * 5 + (9 * 3) * (3 + 9)) + (3 * 4 + 9 * 6)
+(7 + 8 + 6 * 8 * 2) * (8 * 8 * 9 * 5 * 8) + 7 * 2
+(6 + 6 * 6 + 5) + (9 * 9 + 4 + 5 * (8 + 3 + 3 * 6 + 2 + 7)) * 4 * 2 + 9
+(7 + 8 + 5 * 8 * 6 * 2) * 3 * 2 * 6 + 9
+6 + 3 * (2 + 4 + (6 + 4 * 7) * 4)
+4 + 7 * (3 * 9 + (3 + 2) + 7 * 7) + (9 * 2)
+3 * (2 * 6) + 3 * 2
+(4 + 4 + 5 + 7 + 6) + 9 + 4 * 2
+7 + (5 + 8 + (5 + 6 * 9 + 7 + 2 * 8) * (9 * 9 + 6 * 6))
+(5 + (2 * 5 * 9 * 8 + 2 + 7) + 8 * 8) + 4 * 8 * 4 + 8 * 3
+8 * 7 * (3 * 7 + 2 * 3 + 7 * 6) * 3 + (7 + 3 + 6 * 4)
+5 + 4 + 4 + ((6 + 2) * 7 + 6) * (3 * 6 + 6) * 4
+4 * ((2 + 4 + 9) + 8 + 8 + 8) + 5 * 6 * 4
+(2 * 9 * 4 + 6) * 4 * 6 + 7 + 7 * 4
+7 * 2 + 6 * 6 * 4 * ((7 + 2 * 7 + 2 * 9 * 9) + 6)
+(5 * (6 * 3 * 9 * 4 + 9 + 7) * 3 * (9 + 5 * 3 + 3 * 9 * 7) * 7 * 8) + 7
+8 + (6 * (9 + 4 + 6 + 8))
+8 * (6 + 6) * 7 + (8 + 5) + (7 * 3 * 2 + 2 * 9)
+7 * (5 + 9 + 2 * 7 * 3)
+(7 + 5 * 6 * (9 * 8 + 2 * 7)) * 7 * 4 * 7 + 6
+3 * (3 * 3 * 5 + 4 + 9 + 8) + 8 * 5
+(2 + 5 + 2 + (9 * 9 + 9 * 9 + 4) + 9) * 2 * (7 + 6 * (9 * 9 * 2 + 9 + 9))
+2 + 5 + 7 + (5 * 3 + (4 + 8 * 3 * 5)) * 6
+7 * (3 + 9 + 4) + 3 * 9
+9 + 5 * (5 * (5 * 8 + 2 * 7 + 9 * 3)) + 9
+7 * 5 + 2 + 4 * (3 + 9 + 7 * 6 + 3) * 5
+4 + ((5 + 5 + 6 * 9 * 3) * (6 + 4 * 9 + 7 * 5 + 7) * 4 * 7) + ((3 * 3 * 7 + 7) * 3 + 3 * (3 + 5 + 2 * 7 + 4 + 4) + (8 * 5 * 6 + 4 + 2 + 5))
+4 * ((5 * 8 + 7 + 3 + 4 * 2) + 8 * (5 * 7 + 6) * 5 + 3) + 2 * (7 + (9 + 2 + 7 * 5) * 4 + 4 * 9 * 8) + 6 * 9
+5 + 7 + 5 * (6 + 7 * 4 + 7) + 2 + 3
+9 + 3 + (8 + (2 + 3 + 6 * 4 * 8 * 6) * 3 * 7 + 6) * 5
+3 + 5 + 5 + 9 * (3 * 5 + 6) + (6 + 3)
+4 + 3 * (3 + 5 + 4)
+(8 + 2) * 9 * (4 + 2 * 4 + (6 * 7 + 3 * 4 + 5 + 6) + 4 + 2) * 5 + 9 + 2
+(2 + 2 * 6 + 2 * 6 + 4) + 6 + 9 * 3 + 7 + 6
+(3 + (6 + 6 * 8)) * 6 + 7 + (8 + 5 * 5 * 2 + 2 + 9) * 8 * 3
+5 + 6 * (4 * 5 * 7 * 5 + 7 + 2) + 6 + (2 * 2 * 6 * 8) * 3
+(9 * 9 + 6 + 3 + (9 + 8 * 3 + 6 * 6 + 7)) * 8 * 2 * 2 + 6
+(7 * 4) * 3 * 2 * (5 * (8 + 9 + 7 + 6) + 5 * 3 * 6)
+5 + 7 + (6 * 2 * 9 + 8 * (7 + 4 + 4 * 6 + 3) + (5 * 9 * 3 * 8)) * ((2 + 7 * 9 * 3 + 6 * 6) * 3)
+3 * (9 * (7 * 8 + 6 + 3 + 3) * 9) + 8 * 3
+3 * 8 * 9 * 8
+4 + 3 * 4 + 4 * 6 + 4
+8 + 3 * 3 * 3 * (6 + 3 + 3) * (2 * 5 * (9 + 4 + 6 + 9 + 4 * 5) * 8 + 5 + 4)
+9 * 9 + 4 + 7 * 6
+3 + 5 + 3 + 3 * ((3 + 8 + 3 + 3) + 9 * 7 + 4 + 6)
+7 + ((4 * 6 + 8 * 8) * 6 * 9 + (8 * 8 * 2)) + 2 * 3 * 4 + 7
+(2 * 5 * 7 + 2) + (4 + 9 + 3)
+7 + 4 + 4 + (8 * 7 * (7 + 2 + 2 + 4 + 5 + 9) * 2 + 9 + 4)
+2 + ((6 + 3 * 9 + 3 + 5 + 8) * 8 * (5 + 4 + 9 * 6 + 2) * 6 + 8 * 8) * (8 + 2 * 6) + 6 * 8 * 4
+3 + (6 * 9) + 7 * ((8 + 4 * 9 * 9) * 9 * 8 + 3) * 8
+6 + ((6 + 7) * (9 + 2 + 5 * 3 * 3 + 5) + (6 * 3)) * ((5 * 3 * 2) * 6) + 4 * (2 + 5 + 6) * 7
+9 * 6 + 4
+3 * 7 * 3 + 9 + 2 * (3 * 2 + 7 + (6 * 3 + 5 * 5 + 3 * 2))
+(9 + 4 + 6) * 9 * (8 * 3 + 5 + 4) * 8 * 6 * 5
+((6 * 2 + 6 + 6 * 8 * 9) * 9 + 5 * 8 * 5 * 9) + (8 * 9 + 3 * 7 + 6 + 9) * 9 * 4 * 2
+2 * 9 + 5 * (3 * 4 + 5 + 8)
+2 * 4 + (7 + 9) + 5
+5 * (2 * (3 + 5) + 3 + (3 * 3 * 3 * 3 * 8) + 3 + (2 + 7)) * 6 * 2
+7 + (5 + (8 * 5 + 9 + 5 * 9 * 2) * 5 + (4 * 4 * 3))
+4 + ((3 + 2 + 2 * 7 + 3) + (7 + 5 + 2 * 3 * 3) + 7) + 6
+7 * ((2 + 7 + 2 + 4 + 3) + 5) * 6 * 9 * (5 * 2 * 9 * 5 + (9 * 6) + (4 + 3 * 3 * 9))
+7 * (5 + 3) + 6 * 5 * 3 + 6
+3 * 7 + 3 + 5 * (3 * 7 * 4)
+6 + 9 + (5 * 3 + (5 + 7 + 9 * 3 * 9) * 7 + 5 * 8)
+4 + ((6 * 8 + 5) * 2 + 7 + 3 * 7) * 3 * (3 + 4)
+(9 * 7 * 4 * 3 * 7) + 3 * (6 + 2 * 6 * 7 + 6) + 6 + 5
+((7 * 9 * 3 * 5 * 7 + 9) * (2 + 7 + 6 + 4)) * 9 * (5 + 3 + 3 * 7)
+4 * 3 + 5 * (3 * 8 + (2 * 3) + (7 + 8 + 9 + 8) + (4 * 4 * 8))
+(6 + 2 * 8 + 7) + (3 * (9 + 2 + 4 * 7 + 5) * 5 + 7 + 5) + (5 * (5 + 8 * 9 + 4 + 2 * 7) * 7 + (5 + 5 * 7 + 8 * 7)) * (4 + (6 + 6 + 6 + 9 + 9 + 9) * 8 + 8) + 9
+5 * (6 * 7 * 5 + 6) * 2 + (7 * 2 * 2 * 9 * 4) + 2
+(6 + 4 * 6 + 2 * 5 + 9) * 6 + 4 * 5
+3 * 2 + 8 * (9 * 5 + 8 * (8 + 4 * 7 + 5 * 4) * 4 * 7)
+9 + 7 * 6
+6 + 6 + (2 * (4 * 3 * 7 * 4 * 8 + 2) * 6 * 2 + (2 * 5 * 8 + 9 + 8 + 6) * 3) * 4
+8 + 5 + 9 + (4 * (8 * 4 * 7 + 3) + 3 + 8) * 6
+3 + (6 + 3 * (4 * 3 * 7) + 8 + 8) * ((9 * 5 * 4) * 5) * (9 + 9 + 8 + 9 + 7 + 8) + 7 + (5 * 5 + 4 * 9 + (7 * 9 + 6 + 7))
+2 + (8 * 7 * 8 + (8 * 9) * 6) * 3 * 4 + (9 * 4 * 2)
+7 * 4 + (9 * 9 * 2 + 6) * 4 * (3 + 6 * 4 * 9 * 6)
+5 * 7 + 8 + 7 + 4
+3 * (7 * 6 * (9 + 9 + 7 * 6) + 3 + 4) * 3 + (4 * 3 + 8 * 5) * 8 + 9
+6 + (8 * (2 * 2 + 8 * 2 + 4) + 6 * 2 * 3 + 3) * 8 + 4 * 7 * ((9 + 2 + 5 * 7 * 9 * 7) * 4 * 4 + 9 * 3 + 4)
+4 * 6 * (5 * 9) * 8 + (8 * 7)
+8 + ((9 * 4 + 6 + 3 + 7) * 5 + 6 * 2) + (4 * 9 * 9)
+(6 * (5 * 5 + 6 + 6 * 4) * 6 * 3 + 6 * 4) * 7 * 8
+4 + (6 + 7 + 4 * 3 * (6 * 4 + 8))
+((6 + 2) + 2) * 6 * 7 * ((6 * 5 + 8 * 3 + 2) * 3 + 9 + 3 * 7 * 6)
+(5 * (4 * 8 + 2 * 8) * 2) + 3 + 2 * 3 + 3 * 7
+(8 + 3 + (5 * 9 * 8) * (8 + 2 + 6 * 9) * 6) + 9 * 8 + 7 + 6
+((5 + 4 + 7) + (6 * 4 * 9 + 2 + 5 * 4) + 5 + 4 + 6) * 7 * 3
+(3 * 3) + 7 + 9 + 4 + ((8 * 4 + 7) * (6 + 2) * 6)
+5 * 6 * 5 + 3 + (3 * 6 + 7 + 6 * 3 * 2)
+9 * 6 * 5 + 9 * (7 + 3 + (4 * 8 * 4) + 9)
+5 + 5 * (8 * 8) + 3 * (6 + 6) * 5
+(3 * 2) * 3 * 4 + (3 * 7) + 3
+5 * 4 + (9 + 3 + (3 * 2 * 4))
+(7 * 3 * 6 + 7 + 6 * 5) * (9 + 8 * 3) * (7 * 6 + 7) * 7 * 2
+(6 * 7) + 4 + 8 * 8 + 4 + 6
+3 + ((4 * 7 + 9 * 4 * 4 * 9) + (8 + 4 + 5 * 4 * 2) + (4 * 5 * 2) * 3)
+(2 + 7 + 5 * 5) * 9 + 9 * (5 + 7 * (4 * 3 * 3 * 6 * 9 + 2) + 4 + 8) * 6 + 5
+9 + 5
+6 + 9 + (7 + (3 * 7 * 6 + 6 + 7 + 4) * 9) * 8 + 8
+3 * 3 * 7 + ((9 * 7 * 3 * 5 + 4 * 8) + (8 * 4 + 3) + 4 * 4 + 6 * (8 * 8)) + 6 * 8
+(6 * 7) + 6 + ((7 * 3) * 2 + 7 + 2) * 6 * 5 * 3
+(9 + 5 + 8 + 3) + (2 * 4)
+7 * 2 * 8 + 3 + (7 + (7 + 5 * 8 + 3 * 8)) + (2 + (2 + 3 + 3 + 2 * 2 * 9) * 9 * (5 * 9))
+(7 + (8 + 7 + 3 + 8 + 4)) + 4 + 7 * 5
+3 + ((6 + 9 * 6 * 6) * (9 * 2 + 3) + 6 + 2) * 6
+(9 * 2 + 5 + 7) + 3 + ((5 * 8 + 6 * 4 + 8 + 7) + 2 + 7 * 2 * 6 * (2 + 7 + 4)) + 2 + 6
+5 * 4 + (6 + 7 * 4) * 9 + 3
+(7 + 8 * 2 + 9) * 2 * 7 + 4 + (3 + 5 + 3 * 6 * 5 + 2) + 2
+(4 * (3 + 9) * 8 + (3 + 3 * 3 * 8 * 6 * 4) + 5) + (3 * (6 + 7 * 6 * 3 + 5) + (8 + 4 * 6 * 4) * 4 + 2) * 5 * 2 + ((7 + 4 * 9 + 5 + 6) * 4 * (8 + 8 * 2 * 2)) + 9
+3 + (8 + 2 + 3 + 9) + 6 + (9 * 3 * 6) * 2 * 8
+2 + 8 * (3 + 2 + (6 + 8 + 2 + 5 + 4)) * 8
+9 * ((7 * 4) * 3) * 3 * (3 + 2 + 7 + 2 + 5) + 9
+8 + ((2 + 6 + 4) + 7 * (4 * 7 + 3) * 5 + 9 * (3 * 9 + 5 * 9 * 4 + 8))
+8 + (8 * 6 * 4 * (8 * 3 + 9)) * 3 * 9 * 7
+(4 * 3 + 8) + (4 + 2 * 5 * 4 * 8 + 5) * 6 * 3 + (4 * (7 + 5 * 3 + 8 + 6) * 3 + 4 + 7)
+(7 + 4 * 3 * 7 * 4 + 6) + ((3 + 6 + 3 + 2 + 2) * 8) * 4 * 3 + 3
+5 + 7 + (8 + 9 * (6 + 8) + (8 + 4 + 3) * (4 * 7 + 2 + 7 * 8 + 7) * (6 * 7 + 9 + 2 * 5)) + 4 * 7
+(6 + 7 + 2 * (9 * 7 * 5 + 2 + 3) + 6) * 7
+9 * ((2 * 7 + 3) * 3 + 7 + 4) * (9 + 7 + 9 * (4 * 7) + 3) + 9 + 2 + 2
+((2 * 6 * 9 + 4 + 2 + 5) * (6 * 9 * 6 + 9 + 3 * 2) + 8) * 2
+2 * (9 + 9 + 8) + 8 + 5 + (7 * 9 * 4 * 7 * 7 + (4 + 8 + 5 * 7 + 6)) + 2
+(7 * 9 * 8) + (3 + 3 * (6 + 7)) * 9
+(6 + 8 + 7 * (6 + 4 + 8 + 4 + 9 * 2)) + 6 * 5 + 5 + 6
+(7 * 3 * (9 + 3 * 5) + 9 + 4 + 5) + 5 + 9
+((9 + 9) + (9 * 8 + 9 * 7 + 9)) * (9 * 4 * 5) * 4 + 5 + (3 * 5 * 3 * 2) * 5
+5 + 6 + 6 * 3 + (2 * 2)
+4 + ((5 + 3 + 4 + 8) * 5 + 8 * 6 + 3) * ((4 * 2 * 2) + (2 * 9 * 3 + 7) + 5) + 5 + 4 + 4
+9 + (4 + (7 * 6 + 5 * 9) * (9 * 3) + 6 * 2) * 3 * 2
+(5 * 8 * (3 + 5 * 9 + 3) * 6 + 4) + 2 + 6 * 4
+2 * (8 * 4 * (8 + 2) * (9 + 2 + 3 + 2 * 3)) + (7 + (7 * 8 * 3 + 8 * 7 * 4) * 4 * 3 + 9 + 3) * 2 + 4
+2 + (3 * 2 * 3 * 6 + (7 * 3 + 9 + 5 + 8)) * 5 + 3 + ((9 + 7 + 5 * 5 * 7 * 7) * 2 * 7 + 3 * (3 + 4)) + ((3 * 2 + 3) + 7 + 5 * 9 + 8 + (8 + 6 + 9 + 8))
+5 * ((6 * 6) + 2 + 6 * (6 + 2 * 5 + 3) * 5 + 5) * 7 * 5 * 8 * (6 * (8 + 9) * (9 * 6 * 9 * 7 + 5) * 8)
+2 + 6 + (2 * 9 * 3 * 4 + (5 + 9 + 7 + 4 + 4 * 9)) * 5 + 2 * 9
+8 * 7 + 6 * 9 + 8 * (4 + 7 * 2 * (6 + 5) * 5)
+(6 * 2) + (9 + 3 + 9 + 2)
+(8 * (6 + 4) * (3 + 6 + 6 * 7 * 2 * 3) + 4) * ((9 * 2 * 3 + 3 * 6 + 8) + 5 + (7 + 3) * 7 * 3 * 5) + 7 * 5
+7 + (2 + 7 + 4 + (3 + 3 * 3 * 5 * 4) + (2 * 6 + 6 + 9)) * (7 + 7) * 6 * (2 * 5 * 5 * 6 + 5 + 8)
+5 * 3 + 4 + 3 + (6 * 7 * 4 * (2 + 5 + 3 + 8) * 9 * 7)
+5 + 6 * (4 * 4 + 8) * ((2 + 4 + 8 * 5) + 7 * 8 + (5 * 4 + 9 + 7 + 9) * (6 + 7 * 9 * 7 * 7) + (6 + 7 * 7 * 6 * 3 + 4)) + 6 + 5
+5 + 2 * 6 + (6 * 4) * 7
+4 * 7
+(5 + (3 * 8 + 2 + 7 + 6) + 6 * (8 + 6) * (9 + 3 * 6 * 7 + 2) + (8 * 2 * 6 + 7 * 7)) + 7 + 6 + 3 + 7
+9 * 8 * (9 + 9 + 4 + 5) * (6 + 6 * 7)
+(2 * 9 + 2) + 7 + (8 * 5 * 6) * 5 * (7 * 4 * 5 + 6 * 8 + 3) * 8
+2 + 9 + (3 * 5 * 4 * (9 * 4 * 3 * 3 + 2)) * 4 * 6 + 2
+9 * 9 * (4 * 4) * (6 * 7 + 8 * 7 * 4) * 8 + 2
+(4 + 7 * 7) + 2 + 3 * (2 * 2 + 2) * (2 * 5 * 2 + 3 * 5)
+4 + 9 + (3 + 5 + 3) + 9
+6 + (4 * 2 + 6) + (6 + (8 * 6 + 3 * 5 + 6 * 8) * 8) + 4
+6 * (8 + 4 * 8 + 6 + 3 + 7) + 9 + (2 + 8) + 4
+9 + 4 * 7 + 2 + 2 + (6 + 9)
+7 + 3 + ((8 * 3 + 7) * 7 * (8 + 6) + 5 + 8) * 4
+6 + ((2 + 2 * 9) + 2) * 8 + 3 + 4
+((5 * 6 + 4 * 6 + 3) * 4 * (2 * 9 * 2 + 7 + 7) * 4 + 2 * 3) * 4
+2 * 3 + 5 * ((4 * 9 + 6 * 5 + 4) * (2 + 9 * 7 + 7 * 8 + 7) * 6 + 5 * 4 * 6)
+(7 + 7 * 6 * 3 + 4) + 4 * 8 * 7 * 6 * (9 + 8 + (8 + 2 + 7 + 8 * 7) + (4 + 7 + 7 + 6) * 5)
+6 * (8 + 8 * 4 * 8 + 4 + 5) + 8
+(4 * (6 * 5 + 8 + 7 * 4) * (5 + 4 + 3 * 7 * 8 * 4) + 6 * (3 + 6) * 8) + 3 + (5 * (6 + 6 + 8) * 4) + 2 * ((8 * 9 * 8) + (9 * 8 * 9 * 9 + 8 + 7) + 7)
+4 * (9 * 3 + 8 + 4 + 4) * 5 * 5
+7 + ((6 * 6 + 2) + 4 * 3 * 8 + 4)
+(8 + 4 * 3 * (9 + 4) * 5) * 6 * 6
+(3 * (7 + 3) * (5 + 6) + 5 * 5) * 3 * 7 * 5 + 5 + 8
+2 + (4 + 8 + (5 + 6)) * 5 * 4 * 9
+6 * 3 + 3 * 3 + 5 * (9 + 8 * 5 * 3 + 3 * 3)
+(3 + 8) + 4 * (4 * (4 + 5 + 9 + 3 * 6 * 9) + 9 * 9 + (4 + 2 * 7)) * 7 + 2
+(2 + (8 + 2 * 3)) + (3 * 2 + 5 * (4 + 2 + 8) + (9 + 5 + 3 * 6)) + (3 + 9 * (3 * 2 * 5 + 3))
+2 + (7 + 4 * (6 + 4 * 6) + 3 * 8) + 5 * 2 + 5
+((6 * 2) * 8 * 7 * (7 + 9 * 6) + 2) * 2 * 7 + 9 + 4
+6 * (5 * 6) + 3
+(8 + 8 * 7 + 8 * 6) * (8 + 4 * (5 + 9 + 8)) * (3 * 2 * 9 * 4 + 7 * (3 + 4)) + 7
+2 * 8
+4 + 3 + 3
+5 + (5 * 8 + 5 + 9 * 9 * (9 + 4))
+(8 + 5) * (7 + 5 + 2) + 5 * 8 + ((9 * 5) * (7 + 5 + 6 + 7) * 6)
+(2 * 2 * 3 + 6 * 5 + 8) * 3 + 3
+((6 + 7 + 9 + 6 + 3) + 5 + 7 + (4 * 7 + 2) + 5) + 6 + (2 * 6)
+2 + 6 + 6 + (7 * 8 * (4 + 5 * 8 * 6 * 3 * 7) * (3 + 8 * 9 + 8 + 4)) + 5
+8 * 9 + (8 * 7 * 4 * (7 * 6 * 8) + (8 * 6 + 8))
+(6 * 5 * (9 + 7 * 2 * 8 + 7 * 6)) * 6 * 5
+((3 * 5 + 5) + 2 + (5 + 4 + 7) + 6 * (8 + 2)) * 7
+5 + (5 * 6 + 8 * 2 * (7 + 9 + 9 + 3 + 9 * 4) + 5) * 6 + 6 * 9
+8 + 4 * 6 + 5
+(7 * 2) * 9 * 9 + 5
+(3 + 7 * 4 + 8 + 4 * (5 * 6)) + 2 * 4 * 5 + 4
+(9 * (4 + 4 * 5 * 2 * 2) * 9 * (9 * 9 + 3 * 9 + 4 * 3) + 8 * 6) + (2 * 6 * 5 * (3 + 2 + 8 * 8) + 2 * 5) * 7 + 2
+(4 * (7 * 7 * 7 + 5 + 7 * 9) + (4 + 9 + 8) + (3 * 6)) + 6 + 3 + 8
+6 + (3 * (5 + 3 + 7 + 5 * 5 * 3)) + (9 * (6 + 6 * 4 + 2)) * 7
+(8 + (5 * 3) + 5) + 8 + ((5 * 7) * 3 + (4 + 3 * 6 + 6) * 8 * (9 + 7 + 8)) * 7
+7 * 7
+4 * 8 * 5 + 7
+3 + ((4 + 4 + 5 + 5 + 3) + 5 + (4 * 3 * 9 * 4)) + 7
+(2 + 8 * (6 * 2 + 4 * 6) * 8 * 7 + 7) + 5 + (8 + 7 * 3)
+8 * (7 * 3 + (9 + 3 + 7) * 3 + 2 + 8) * 9 * 6 + 8 + 7
+9 * 9 + 9 * (9 + 2 + (8 + 9 * 4 + 3 * 4 * 9) * 9 * (8 + 5 + 7) + 3) + 7
+(7 * 6 * 5 * 6) + 6
+3 * 5 * 7 + 2 + (9 * 8 + (9 + 7 * 8) * (6 * 8 * 4 * 7 * 9) * 7) * 4
+2 * 3 * 6
+3 * (7 + 6 + 4 + (3 * 3 * 2 * 2 * 5) * 7 * 6) + 3 * 8 * (3 + 4 + 8 * 9 + 2)
+(6 + 6 * 6 + 4) * 6 + 6 + (7 * 6 + (2 * 3 + 3 * 4 + 6) + (9 + 7 * 7 * 3 + 3))
+2 * (7 * 3 * 7 + 5 * 9) * 5 * 6 * 6
+3 + (7 + 4 + 4) + 9 + (8 * 6 * 7)
+(6 + (7 + 5 * 9 + 8 + 9) + 2 + 4) * (2 * 4 + 3 + 2 * 9)
+2 + (9 + 8 * 9 + 9 + 8 * (8 * 9 * 3 * 6 * 5)) + 6 + 3 * 6
diff --git a/2020/src/day18.rs b/2020/src/day18.rs
index b7b5383..5edd067 100644
--- a/2020/src/day18.rs
+++ b/2020/src/day18.rs
@@ -1,12 +1,187 @@
 use std::io::Read;
 
+use crate::common::Lines;
 use crate::Solution;
 
+#[derive(Clone, Copy)]
+enum Op {
+    Addition,
+    Multiplication,
+}
+
+fn extract_brackets(with_brackets: &str) -> (&str, &str) {
+    let mut brackets = 1;
+
+    let mut end = None;
+
+    for (i, c) in with_brackets.chars().enumerate().skip(1) {
+        match c {
+            '(' => brackets += 1,
+            ')' => brackets -= 1,
+            _ => {}
+        }
+
+        if brackets == 0 {
+            end = Some(i);
+            break;
+        }
+    }
+
+    let end = end.expect("Unmatched brackets");
+    let next_start = with_brackets.len().min(end + 2);
+
+    (&with_brackets[1..end], &with_brackets[next_start..])
+}
+
+fn compute_value(expression: &str) -> u64 {
+    let mut remainder = expression;
+    let mut value = 0;
+    let mut op = None;
+
+    let mut apply_value = |n, op| match op {
+        Some(Op::Addition) => value += n,
+        Some(Op::Multiplication) => value *= n,
+        None => value = n,
+    };
+
+    while !remainder.is_empty() {
+        let pos = remainder.find(' ');
+
+        let part = if let Some(pos) = pos {
+            &remainder[..pos]
+        } else {
+            remainder
+        };
+
+        match part.chars().next().unwrap() {
+            '+' => op = Some(Op::Addition),
+            '*' => op = Some(Op::Multiplication),
+            '(' => {
+                let (in_brackets, rest) = extract_brackets(remainder);
+                remainder = rest;
+                let n = compute_value(in_brackets);
+
+                apply_value(n, op);
+                // Skip the remainder update
+                continue;
+            }
+            c if c.is_ascii_digit() => {
+                let n = part.parse().unwrap();
+                apply_value(n, op);
+            }
+            _ => panic!("Not a valid expression part {}", part),
+        }
+
+        let pos = pos.map(|n| n + 1).unwrap_or(remainder.len());
+        remainder = &remainder[pos..];
+    }
+
+    value
+}
+
+fn compute_value2(expression: &str) -> u64 {
+    let mut remainder = expression;
+    let mut value = 0;
+    let mut result = 1;
+    let mut op = None;
+
+    let mut apply_value = |n, op| match op {
+        Some(Op::Addition) => value += n,
+        Some(Op::Multiplication) => {
+            result *= value;
+            value = n;
+        }
+        None => value = n,
+    };
+
+    while !remainder.is_empty() {
+        let pos = remainder.find(' ');
+
+        let part = if let Some(pos) = pos {
+            &remainder[..pos]
+        } else {
+            remainder
+        };
+
+        match part.chars().next().unwrap() {
+            '+' => op = Some(Op::Addition),
+            '*' => op = Some(Op::Multiplication),
+            '(' => {
+                let (in_brackets, rest) = extract_brackets(remainder);
+                remainder = rest;
+                let n = compute_value2(in_brackets);
+
+                apply_value(n, op);
+                // Skip the remainder update
+                continue;
+            }
+            c if c.is_ascii_digit() => {
+                let n = part.parse().unwrap();
+
+                apply_value(n, op);
+            }
+            _ => panic!("Not a valid expression part {}", part),
+        }
+
+        let pos = pos.map(|n| n + 1).unwrap_or(remainder.len());
+        remainder = &remainder[pos..];
+    }
+
+    result * value
+}
+
 #[derive(Default)]
 pub struct Day18;
 
 impl Solution for Day18 {
-    fn part1(&mut self, _input: &mut dyn Read) -> String {
-        todo!()
+    fn part1(&mut self, input: &mut dyn Read) -> String {
+        Lines::new(input)
+            .map(|l| compute_value(&l))
+            .sum::<u64>()
+            .to_string()
+    }
+
+    fn part2(&mut self, input: &mut dyn Read) -> String {
+        Lines::new(input)
+            .map(|l| compute_value2(&l))
+            .sum::<u64>()
+            .to_string()
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn sample_part1() {
+        assert_eq!(71, compute_value("1 + 2 * 3 + 4 * 5 + 6"));
+        assert_eq!(51, compute_value("1 + (2 * 3) + (4 * (5 + 6))"));
+        assert_eq!(26, compute_value("2 * 3 + (4 * 5)"));
+        assert_eq!(437, compute_value("5 + (8 * 3 + 9 + 3 * 4 * 3)"));
+        assert_eq!(
+            12240,
+            compute_value("5 * 9 * (7 * 3 * 3 + 9 * 3 + (8 + 6 * 4))")
+        );
+        assert_eq!(
+            13632,
+            compute_value("((2 + 4 * 9) * (6 + 9 * 8 + 6) + 6) + 2 + 4 * 2")
+        );
+    }
+
+    #[test]
+    fn sample_part2() {
+        assert_eq!(231, compute_value2("1 + 2 * 3 + 4 * 5 + 6"));
+        assert_eq!(51, compute_value2("1 + (2 * 3) + (4 * (5 + 6))"));
+        assert_eq!(46, compute_value2("2 * 3 + (4 * 5)"));
+        assert_eq!(1445, compute_value2("5 + (8 * 3 + 9 + 3 * 4 * 3)"));
+        assert_eq!(
+            669060,
+            compute_value2("5 * 9 * (7 * 3 * 3 + 9 * 3 + (8 + 6 * 4))")
+        );
+        assert_eq!(
+            23340,
+            compute_value2("((2 + 4 * 9) * (6 + 9 * 8 + 6) + 6) + 2 + 4 * 2")
+        );
     }
 }