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:
    bangun[0] = int(bangun[0]) - 1
    bangun[1] = 60
    menit1 = 60 + menit
    A = str(menit1)
    if len(A)<2:
        A = "0"+A
    jam = int(bangun[0]) - int(lama_tidur[0])
    jam_tidur = str(jam)+":"+A
    if jam < 0:
        jam1 = 24 + jam
        jam_tidur = str(jam1)+":"+A
        if len(str(jam1)) < 2:
            jam1 = "0"+str(jam1)
            jam_tidur = jam1+":"+A
else:
    jam = int(bangun[0]) - int(lama_tidur[0])
    A = str(menit)
    B = str(jam)
    if len(A) < 2:
        A = "0"+A
    if len(B) < 2:
        B = "0"+B
    jam_tidur = B+":"+A
    if jam < 0:
        jam1 = 24 + jam
        if len(jam1) < 2:
            jam1 = "0"+jam1
        jam_tidur = str(jam1)+":"+A
print(jam_tidur)
 	 	 				  	 		 	  	  	 			 	 	