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.
h1, m1 = map(int, input().split(':'))
h2, m2 = map(int, input().split(':'))
t = h1 * 60 + m1 - h2 * 60 - m2
h = t // 60
h %= 24
m = t % 60
print(str(h // 10) + str(h % 10) + ':' + str(m // 10) + str(m % 10))