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=input()
t=input()
x=int(t[:2])*60+int(t[3:])
y=int(s[:2])*60+int(s[3:])
if(y-x)<0:
      z=1440-(x-y)
      a=str(z//60)
      b=str(z%60)
      if(len(a)<2):
            a='0'+a
      if(len((b))<2):
            b='0'+b
      print(a+":"+b)
else:
      z=(y-x)
      a=z//60
      b=z%60
      if(len(str(a))<2):
            a='0'+str(a)
      if(len(str(b))<2):
            b='0'+str(b)
      print((a)+":"+(b))
