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.
h,m = [int(x) for x in input().split(":")]
hdiff, mdiff = [int(x) for x in input().split(":")]

m1=m-mdiff
h1=h-hdiff
if m1<0:
  m1=60+m1
  h1=h1-1
if h1<0:
  h1=24+h1
h1=str(h1)
m1=str(m1)
print(h1.zfill(2)+":"+m1.zfill(2))