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

    plus = float(S[3:]) - 9
    h = int(A) + plus
    m = int(B) + (plus % 1) * 60

    if m >= 60:
        m -= 60
        h += 1

    if h > 23:
        h -= 24
    elif h < 0:
        h += 24

    print(f'{int(h):0>2}:{int(m):0>2}')

main()