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(":")
h = int(s[0]) - int(t[0])
if h < 0:
    h += 24
m = abs(int(s[1]) - int(t[1]))
h, m = str(h).zfill(2), str(m).zfill(2)
print("%s:%s" % (h, m))
