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.
def minutes(x, y):
    return x * 60 + y


a, b = map(int, input().split(':'))
c, d = map(int, input().split(':'))
delta_time = minutes(a, b) - minutes(c, d)
if delta_time < 0:
    delta_time += 24 * 60
print("%02d:%02d" % (delta_time // 60, delta_time % 60))
