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(":")

start = int(s[0])*60 + int(s[1])
time = int(t[0])*60 + int(t[1])

ans = start - time

if ans < 0:
	ans = 24*60 + ans

hours = ans // 60
minutes = ans % 60

if hours < 10:
	print("0{}:".format(hours), end="")
else:
	print("{}:".format(hours), end="")

if minutes < 10:
	print("0{}".format(minutes))
else:
	print("{}:".format(minutes))