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.
h,m = map(int, input().split(':'))
h += 23
m += 60
th, tm = map(int, input().split(':'))
h = h - th
m = m - tm
h = (h + m//60) % 24
m = m % 60
if h < 10:
    h = '0'+str(h)
if m < 10:
    m = '0' + str(m)
print(str(h) + ':' + str(m))