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.
now = input()
dur = input()
a=int(now.split(':')[0])
b=int(now.split(':')[1])
c=int(dur.split(':')[0])
d=int(dur.split(':')[1])

if b>=d :
	min = b-d
if d>b:
	min = 60 + b-d
	a -= 1
if a>=c :
	hour = a-c
if c>a :
	hour = 24 + a-c


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