solve :: [Code] -> String
solve = concatMap runCode
  where
    runCode (Raw s) = s
    runCode (Repeat n s) = concat $ replicate n s
solve :: [Code] -> String
solve = concatMap runCode
  where
    runCode (Raw s) = s
    runCode (Repeat n s) = concat $ replicate n s
solve = concatMap runCode
  where
    runCode (Raw s) = s
    runCode (Repeat n s) = concat $ replicate n s