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.
h,m = list(map(int, input().split(':')))
t_h,t_m = list(map(int, input().split(':')))
if m >= t_m:
    m -= t_m
else:
    h = (h-1)%24
    m = m+24 - t_m
if h >= t_h:
    h -= t_h
else:
    h = (h-1)%24
print('{0:02}'.format(h)+':'+'{0:02}'.format(m))