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.
s=str(input())
t=str(input())
p=''
f=int(s[:2])
v=int(t[:2])
g=int(s[3:])
h=int(t[3:])
z=True
while(z):
  if f==00 or f<v:
    f=f+24
  if v==00:
    v=24
  n=f*60+g
  b=(n-(v*60+h))//60
  c=(n-(v*60+h))%60
  if b<10:
    p+="0"

  p+=str(b)
  p+=":"
  if c<10:
    p+="0"
    
  p+=str(c)

  
  print(p)
  z=False

    
     
