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.
fy = list(map(int, input().split(':')))
ft = list(map(int, input().split(':')))
fp = fs = 0
n = (int(fy[0]) - int(ft[0])) % 24
if int(n) >= 10:
    fp = n
else:
    fp = '0' + n
n  = (int(fy[1]) - int(ft[1])) % 60
if int(n) >= 10:
    fs = n
else:
    fs = '0' + n
print(fp +':' + fs)
