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 = input().split(':')
b = input().split(':')



x  = int(a[0]) * 60 + int(a[1])
y  = int(b[0]) * 60 + int(b[1])


if y>x: x = ((int(a[0])+24) * 60 ) + int(a[1])


z = x - y

hr = str(z // 60).rjust(2 , '0')
z %=60
mi = str(z).rjust(2 , '0')

print(f"{hr}:{mi}")

