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.
import datetime
s=input().split(':')
t=input().split(':')
sh,sr=int(s[0]),int(s[1])
th,tr=int(t[0]),int(t[1])
p=datetime.timedelta(hours=sh,minutes=sr)
q=datetime.timedelta(hours=th,minutes=tr)
l=datetime.timedelta(hours=24,minutes=0)
if p>q:
	z=p-q
else:
	z=l+p-q
z=str(z)
z=z.split(':')
z=z[:2]
z=':'.join(z)
print(z)