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.
bangun = input().split(":")
lama_tidur = input().split(":")
menit = int(bangun[1]) - int(lama_tidur[1])
jam = int(bangun[0]) - int(lama_tidur[0])
if menit < 0:
    menit += 60
    jam -= 1
if jam < 0:
    jam += 24
A = str(menit)
B = str(jam)
if len(A) < 2:
    A = "0"+A
if len(B)<2:
    B = "0"+B
print(B+":"+A)
 	  	   		 		   		 		 	   					