George woke up and saw the current time *s* on the digital clock. Besides, George knows that he has slept for time *t*. 

Help George! Write a program that will, given time *s* and *t*, determine the time *p* when George went to bed. Note that George could have gone to bed yesterday relatively to the current time (see the second test sample).
The first line contains current time *s* as a string in the format "hh:mm". The second line contains time *t* in the format "hh:mm" — the duration of George's sleep. It is guaranteed that the input contains the correct time in the 24-hour format, that is, 00 ≤ *hh* ≤ 23, 00 ≤ *mm* ≤ 59.
from sys import stdin


def main():
    (h, m), (dh, dm) = (tuple(map(int, stdin.readline().strip().split(':'))) for _ in (0, 1))
    return '{:0>2d}:{:0>2d}'.format(*divmod(((h - dh) * 60 + m - dm) % 1440, 60))


print(main())
