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(":")))

diff = []

if t[-1] > s[-1]:
    diff.append(s[-1] + 60 - t[-1])
    diff.append(s[0] - t[0] - 1)
else:
    diff.append(s[-1] - t[-1])
    diff.append(s[0] - t[0])        

if diff[-1] < 0:
    diff[-1] += 24
    
print(":".join(["0" + i if len(i) == 1 else i for i in map(str, diff[:: -1])]))