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.
h1,m1=map(int,input().split(':'))
h2,m2=map(int,input().split(':'))
if h1 == 00:
  h1=24
if h2 == 00:
  h2=24
time1=h1*60+m1
time2=h2*60+m2
timex=time1-time2
hx=timex//60
mx=timex%60
if hx<10 :
  hx='0'+str(hx)
if mx<10 :
  mx='0'+str(mx)
  
print(hx,':',mx)