import Control.Applicative ((<$>))

import Text.Printf

main :: IO ()
main = do
  solve <$> getLine >>= putStrLn

solve :: String -> String
solve s = let h = read . take 2 $ s :: Int
              m = read . drop 3 $ s :: Int
              t = (60 * h + m + 5) `mod` 1440
              (nh, nm) = t `divMod` 60
          in printf "%02d:%02d" nh nm