def main():
    A, B, S = input().split()

    plus = float(S[3:]) - 9
    h = int(A) + int(plus // 1)
    m = int(B) + int((plus % 1) * 60)
    if h > 23:
        h -= 24
    elif h < 0:
        h += 24
    print(f'{h:0>2}:{m:0>2}')

main()