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 = input().split(":")
b = input().split(":")
w = int(a[0])*60
w+=int(a[1])
wb = int(b[0])*60
wb+=int(b[1])
c=w-wb
if c<0:c+=1440
h,m=c//60,c%60
if h<9:
    h="0"+str(h)
if m<10:
    m="0"+str(m)
print(str(h)+":"+str(m))
 	 		 		 	 	  					  	  		