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()
b = input()
if int(a.split(':')[0]) - int(b.split(':')[0]) >= 0:
	hour = int(a.split(':')[0]) - int(b.split(':')[0])
if int(a.split(':')[0]) - int(b.split(':')[0])  < 0:
	hour = 24 - int(a.split(':')[0]) - int(b.split(':')[0])
if int(a.split(':')[1]) - int(b.split(':')[1]) >= 0:
	min = int(a.split(':')[1]) - int(b.split(':')[1])
if int(a.split(':')[1]) - int(b.split(':')[1])  < 0:
	min = 60 - int(a.split(':')[1]) - int(b.split(':')[1])

if hour<10:
	hour = '0'+str(hour)
if min<10:
	min = '0'+str(min)
print(str(hour)+':'+str(min))

		 	 			 	 	  	   	  		 		 			