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,b=map(int,input().split(':'));c,d=map(int,input().split(':'));x,y=0,0
if b>=d:y=b-d
else:a-=1;y=60-d+b
if (a-c)<0:x=24+a-c
else:x=a-c
x,y=str(x),str(y)
print('0'*abs(len(x)-2)+x+':'+'0'*abs(len(y)-2)+y)