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.
h2, m2 = map(int, input().split(':'))
h_sleep, m_sleep = map(int, input().split(':'))

t2 = m2 + h2 * 60
t_sleep = m_sleep + h_sleep * 60

t2 -= t_sleep
if t2 < 0:
    t2 += 60 * 24

print('0' * (2 - len(str(t2 // 60))) + str(t2 // 60) + ':' + '0' * (2 - len(str(t2 % 60))) + str(t2 % 60))
