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.
f=input().split(':')
s=input().split(':')
h=int(f[0])
p=int(f[1])
j=int(s[0])
o=int(s[1])
if(h<j or(h==j and p<o)): h=h+24
h=h-j
p=p-o
if(p<0):
    h=h-1
    p=60+p
print('%02d:%02d'%(h,p))