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.
p = input()
s = input()
h1, m1 = map(int, p.split(':'))
h2, m2 = map(int, s.split(':'))
h = (h1 - h2) % 24
m = (m1 - m2) % 60
if m1 < m2: h -= 1
print('{:02d}:{:02d}'.format(h, m))