import strutils, sequtils
proc tt(t: int): string =
  ["", "0"][int(t < 10)] & $t

let T = readLine(stdin).split(':').map parseInt
var t = T[0] * 60 + T[1]
t = (t + 5) mod (24 * 60)

echo (t div 60).tt, ':', (t mod 60).tt