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, = map(int, input().split(":"))
*t, = map(int, input().split(":"))
s = s[0] * 60 + s[1]
t = t[0] * 60 + t[1]
if t > s:
    t -= s
    s = 1440 - t
else:
    s -= t
hh = '0' * (2 - len(str(s // 60))) + str(s // 60)
mm = '0' * (2 - len(str(s % 60))) + str(s % 60)
print(hh + ':' + mm)
