import Data.Char

cntChar x c = length . filter (==c) $ x
cntAlpha x = map (cntChar x) ['a'..'z']

printCnt cntResult = putStr . unlines . zipWith (++) (map ((++ " : ") . (:[])) ['a'..'z']) $ map show cntResult

main =
    getContents >>= printCnt . cntAlpha . map toLower