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.
s1=input()
s2=input()
h1,m1=s1.split(':')
h2,m2=s2.split(':')
m=int(m1)-int(m2)
h=int(h1)-int(h2)-1*(m<0)
print(str(h%24).zfill(2),str(m%60).zfill(2),sep=':')


