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(":")
answer = []
hourWakeUp = int(s[0])
minuteWakeUp = int(s[1])
hourSleep = int(t[0])
minuteSleep = int(t[1])
if minuteWakeUp < minuteSleep:
    minuteWakeUp = minuteWakeUp + 60
    hourWakeUp -= 1
if hourWakeUp < hourSleep:
    hourWakeUp = hourWakeUp + 24
hourAnswer = str(hourWakeUp - hourSleep).zfill(2)
minuteAnswer = str(minuteWakeUp - minuteSleep).zfill(2)
answer.append(hourAnswer)
answer.append(minuteAnswer)
ans = ":".join(answer)
print(ans)

		     	  		  	  	  			 			