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.
h, s = list(map(int, input().split(":")))
h1, s1 = list(map(int, input().split(":")))
a = h - h1
b = abs(s1 - s)
if h1 == 0 and s1 == 0:
    print("{}:{}".format(str(h).zfill(2), str(s).zfill(2)))
elif a == 0:
    print("{}:{}".format(str(a).zfill(2), str(b).zfill(2)))
elif a < 0:
    print("{}:{}".format(str(24+a).zfill(2), str(b).zfill(2)))
else:
    print("{}:{}".format(str(a).zfill(2), str(b).zfill(2)))