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.
s_hh, s_mm = map(int, input().split(':'))
t_hh, t_mm = map(int, input().split(':'))

hh = list(range(0,24))
mm = list(range(0,60))

print(str(hh[s_hh-t_hh]).zfill(2) + ':' + str(mm[s_mm-t_mm]).zfill(2))