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.
a, b = map(int, input().split(':'))
c, d = map(int, input().split(':'))
def pr(c, d): print(c // 10, c % 10, ':', d // 10, d % 10, sep = '', end = '')
if b >= d: d = b - d
else:
    c += 1
    d = 60 + b - d
if c == 24: pr(a, d)
else:
    if a >= c: pr(a - c, d)
    else: pr(24 + a - c, d)