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 = list(map(int, input().split(":")))
t = list(map(int, input().split(":")))
h1=s[0]*60+s[1]
h2=t[0]*60+t[1]
a=(h1-h2 if h1-h2>=10 else h1-h2+24*60)
print(a//60 if a//60>=10 else "0"+str(a//60), a%60 if a%60>=10 else "0"+str(a%60),sep=":")