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
s = datetime.strptime(input(), '%H:%M')
t = datetime.strptime(input(), '%H:%M')

sec = (s - t).seconds
hours, rem = divmod(sec, 60**2)
minutes, sec = divmod(rem, 60)
print(str(hours).zfill(2) + ':' + str(minutes).zfill(2))
