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 = list(map(int, input().split(':')))
H2, M2 = list(map(int, input().split(':')))
Min1, Min2 = H1 * 60 + M1, H2 * 60 + M2
Result = (Min1 - Min2 if Min1 - Min2 >= 0 else Min1 - Min2 + 1440)
print(Result // 60 if len(str(Result // 60)) == 2 else '0' + str(Result // 60), end=":")
print(Result % 60 if len(str(Result % 60)) == 2 else '0' + str(Result % 60))
