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(':'))
if (m1 < m2):
    m1 += 60
    h1 -= 1
if (h1 < h2):
    h1 += 24
r1, r2 = str(h1 - h2), str(m1 - m2)
print('0' * (2-len(r1)) + r1 + ":" + '0' * (2-len(r2)) + r2)
