diff --git a/2017/day-15/Makefile b/2017/day-15/Makefile
index a933dc4..b6dd19e 100644
--- a/2017/day-15/Makefile
+++ b/2017/day-15/Makefile
@@ -2,4 +2,4 @@ all: solution
 	./$<
 
 solution: solution.hs
-	ghc $< -o $@
+	ghc -dynamic $< -o $@
diff --git a/2017/day-15/input.txt b/2017/day-15/input.txt
new file mode 100644
index 0000000..46491bf
--- /dev/null
+++ b/2017/day-15/input.txt
@@ -0,0 +1,2 @@
+Generator A starts with 618
+Generator B starts with 814
diff --git a/2017/day-15/solution.hs b/2017/day-15/solution.hs
index bcc8cde..eb791ba 100644
--- a/2017/day-15/solution.hs
+++ b/2017/day-15/solution.hs
@@ -16,7 +16,7 @@ genB' n = filter (divisible 8) $ genB n
 main :: IO ()
 main = do
     let aStart = 618
-    let bStart = 814
+        bStart = 814
 
     print $ length $ filter judge $ take 40000000 $ drop 1 $ zip (genA aStart) (genB bStart)
     print $ length $ filter judge $ take 5000000 $ zip (genA' aStart) (genB' bStart)