Fix Haskell compilation on Arch Linux.

2017/day-15/Makefile

@@ -2,4 +2,4 @@ all: solution
 	./$<
 
 solution: solution.hs
-	ghc $< -o $@
+	ghc -dynamic $< -o $@

2017/day-15/input.txt

@@ -0,0 +1,2 @@
+Generator A starts with 618
+Generator B starts with 814

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)