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.
a1,a2=map(int,input().split(':'))
b1,b2=map(int,input().split(':'))

if(a1<b1 or (a1==b1 and a2<b2)):
    a1=a1+24

a1=a1-b1
a2=a2-b2

if(a2<0):
    a1-=1
    a2+=60

print("%02d:%02d"%(a1,a2))