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(':')
c1 = int(a[0])-int(b[0])
c2 = int(a[1])-int(b[1])
if c2<0:
    c2+=60
    c1-=1
if c1<0:
    c1+=24
c1 = str(c1)
c2 = str(c2)
if len(c1) == 1:
    c1 = '0'+c1
if len(c2) == 1:
    c2 = '0'+c2
print(c1+':'+c2)
	 	 	    	  			  		  	  		   	