import Text.Printf

solve :: [Int] -> (Int, Int)
solve [h, m] = ((div hm 60) `mod` 24, hm `mod` 60) where
    hm = (h * 60 + m + 5) `mod` (24 * 60)
    

main = do
    hm <- map (read :: String -> Int) . words . (\[a, b, _, c, d] -> [a, b, ' ', c, d]) <$> getLine
    let
        (h, m) = solve hm
    printf "%02d:%02d\n" h m