import Text.Printf

main :: IO ()
main = do
    n <- getLine
    let (h, m) = ((read :: String -> Int) (take 2 n), (read :: String -> Int) (drop 3 n))
        a = h * 60 + m + 5
        (b, c) = a `divMod` 60
        d = b `mod` 24

    printf "%.02f:%.02f" d c