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.
h,m=map(int,input().split(':'))

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


m=m-y

d=1 if m<0 else 0

h-=d
m=m%60

h-=t

h=h%24

h=str(h);m=str(m)
if len(h)==1:h='0'+h
if len(m)==1:m='0'+m
print(h+':'+m)
