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.
end = list(map(int, input().split(":")))
duration = list(map(int, input().split(":")))
start = [0, 0]

ch, cd = 0, 0
if end[1] < duration[1]:
    ch = 1
if end[0] < duration[0] + ch:
    cd = 1
start[1] = end[1] + ch*60 - duration[1]
start[0] = end[0] + cd*24 - duration[0] + ch
if start[1] < 10:
    start[1] = '0' + str(start[1])
if start[0] < 10:
    start[0] = '0' + str(start[0])
print(f"{start[0]}:{start[1]}")