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.
up = list(map(int,input().split(sep=':')))
time = list(map(int, input().split(sep=':')))
a = up[0]*60 + up[1]
b = time[0]*60 + time[1]
if a - b >= 0:
    m = (a-b)//60
    n = (a-b)%60

else:
    m = (24*60 + a -b)//60
    n = (24*60+a-b)%60
print(str(m).zfill(2),str(n).zfill(2),sep=':')