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.
from datetime import datetime, timedelta, time

now = datetime.strptime(input(), '%H:%M')
td = datetime.strptime(input(), '%H:%M')
h = (now - td).seconds // 3600
m = (now -td).seconds // 60 % 60
s = time (h,m)
print(s.strftime('%H:%M'))