-- yukicoder My Practice
-- author: Leonardone @ NEETSDKASU

main = getLine >>= putStrLn . solve

solve s = hour ++ ":" ++ minute where
    h = read $ take 2 s
    m = read $ drop 3 s
    m2 = if m + 5 >= 60 then m + 5 - 60 else m + 5
    ph = if m + 5 >= 60 then 1 else 0
    h2 = if h + ph >= 24 then h + ph - 24 else h + ph
    hour = if h2 < 10 then "0" ++ show h2 else show h2
    minute = if m2 < 10 then "0" ++ show m2 else show m2