main = do
 (h1:h2:_:m1:m2:_) <- getLine
 let h = read [h1,h2]
 let m = read [m1,m2]
 let h' = mod (h + (if m+5 >= 60 then 1 else 0)) 24
 let m' = mod (m+5) 60
 let hs = reverse $ take 2 $ reverse ("0" ++ show h')
 let ms = reverse $ take 2 $ reverse ("0" ++ show m')
 putStrLn (hs ++ ":" ++ ms)