import Control.Applicative ((<$>))
import Text.Printf

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

solve :: [String] -> String
solve [a, b, s] = let (h, m) = (jt + round tt * (if sn == '+' then 1 else (-1)) - 540) `divMod` 60
                  in printf "%02d:%02d" (h `mod` 24) m
  where
    jt = (read a) * 60 + (read b) :: Int
    sn = head . drop 3 $ s
    tt = read (drop 4 s) * 60 :: Double