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 = list(map(int,input().split(':')))
t = list(map(int,input().split(':')))

if s[0] == t[0] and s[1] > t[1]:
  p = str(s[0]-t[0]).zfill(2) + ':' + str(s[1]-t[1]).zfill(2)

elif s[0] < t[0] and s[1] == t[1]:
  p = str((s[0]+24)-t[0]).zfill(2) + ':' + str(s[1]-t[1]).zfill(2)

elif s[0] == t[0] and s[1] == t[1]:
  p = str(s[0]-t[0]).zfill(2) + ':' + str(s[1]-t[1]).zfill(2)

elif s[0] == t[0] and s[1] < t[1]:
  p = str((s[0]+23)-t[0]).zfill(2) + ':' + str((s[1]+60)-t[1]).zfill(2)

elif s[0] < t[0] and s[1] < t[1]:
  p = str((s[0]+23)-t[0]).zfill(2) + ':' + str((s[1]+60)-t[1]).zfill(2)

print(p)