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=input().split(':'),input().split(':')
if int(a[0])-int(b[0])<0:
	c=24+int(a[0])-int(b[0])
	if c<10:
		c='0'+str(c)
else:
	c=int(a[0])-int(b[0])
	if c<10:
		c='0'+str(c)
if int(a[1])-int(b[1])<0:
	d=60+int(a[1])-int(b[1])
	if d<10:
		d='0'+str(d)
else:
	d=int(a[1])-int(b[1])
	if d<10:
		d='0'+str(d)
print('{}:{}'.format(c,d))

	 			  	    	  	          		 		