diff --git a/2015/day10/day10.hs b/2015/day10/day10.hs
new file mode 100644
index 0000000..0d750cd
--- /dev/null
+++ b/2015/day10/day10.hs
@@ -0,0 +1,14 @@
+import Aoc
+import Data.List ( group, sort )
+
+step :: String -> String
+step = concat . concatMap (\cs -> [show $ length cs, [head cs]]) . group
+
+part1 :: String -> (Int, String)
+part1 x = (length after40, after40)
+    where after40 = iterate step x !! 40
+
+part2 :: p -> String -> Int
+part2 _ after40 = length (iterate step after40 !! 10) -- only 10 more needed
+
+main = aocMain' single part1 part2
\ No newline at end of file