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 *
a = input().split(":")
b = input().split(":")
x = datetime(1,1,3,int(a[0]),int(a[1]))
y = timedelta(hours=int(b[0]),minutes=int(b[1]))
z = str(x - y).split(' ')[1].split(":")
print("%s:%s"%(z[0],z[1]))
