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.
s=input().split(':')
t=input().split(':')
x=int(s[0])-int(t[0])
# print(x,s[0],t[0])
if x<0:
	print(x+24,end='')
elif x==0 and (s[0]==t[0]=='00'):
	print(23,end='')
else:
	if x<10:
		print(0,end='')
	print(x,end='')
print(':',end='')
y=int(s[1])-int(t[1])
if y<0:
	y+=60
if y<10:
	print(0,end='')
print(y)