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 = map(int,input().split(':'))
sh,sm = map(int, input().split(':'))
hh = h - sh
mm = m - sm
if mm < 0:
    h -=1
    mm = 60 - abs(mm)
if hh < 0:
    hh = 24 - abs(hh)
if len(str(hh)) == 1:
    hh = '0' + str(hh)
if len(str(mm)) == 1:
    mm = '0' + str(mm)
print(str(hh) + ':' + str(mm))