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[-1]>=t[-1]:
    mm=str(s[-1]-t[-1])
else:
    mm=str(s[-1]+60-t[-1])
    s[0]=s[0]-1
hh=s[0]-t[0]
if hh<0:
    hh=24+hh
hh=str(hh)
if len(hh)<2:
    hh="0"+hh
if len(mm)<2:
    mm="0"+mm
rs=hh+":"+mm
print(rs)