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.
cur_hr, cur_min = map(int, input().split(':'))
dur_hr, dur_min = map(int, input().split(':'))

cur = cur_hr * 60 + cur_min
dur = dur_hr * 60 + dur_min

sleep = (cur - dur)% 1440

sleep_hr = sleep // 60
sleep_min = sleep % 60

print(str(sleep_hr).rjust(2,'0') + ':' + str(sleep_min).rjust(2,'0'))
