fun readInt () =
    valOf (TextIO.scanStream (Int.scan StringCvt.DEC) TextIO.stdIn)


fun readChar () =
    valOf (TextIO.scanStream Char.scan TextIO.stdIn)


val () =
    let
        val h = readInt ()
        val _ = readChar ()
        val m = readInt ()

        val sumM = m + 5
        val nextM = sumM mod 60
        val sumH = h + sumM div 60
        val nextH = sumH mod 24
    in
        print (StringCvt.padLeft #"0" 2 (Int.toString nextH) ^ ":" ^
               StringCvt.padLeft #"0" 2 (Int.toString nextM) ^ "\n")
    end