#!/usr/bin/env python3
# from typing import *

import sys
import io
import math
import collections
import decimal
import itertools
import bisect
import heapq


def input():
    return sys.stdin.readline()[:-1]


# sys.setrecursionlimit(1000000)

# _INPUT = """22 20 UTC+8
# """
# sys.stdin = io.StringIO(_INPUT)

a, b, S = input().split()
m = int(a) * 60 + int(b)
dm = int((float(S[3:])-9) * 10) * 6
m1 = (m + dm) % (60 * 24)

print(f'{m1//60:02}:{m1%60:02}')