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.
DAY_SECONDS = 86400

def get_seconds(s):
    return s[0] * 3600 + s[1] * 60

def seconds_to_time(s):
    h = (s // 3600) % 24
    m = (s // 60) % 60
    return "{0:02d}:{1:02d}".format(h, m)

def solve(s, t):
    s = [int(x) for x in s.strip().split(":")]
    t = [int(x) for x in t.strip().split(":")]
    sec = get_seconds(s) - get_seconds(t)
    sec = sec if sec >= 0 else DAY_SECONDS + sec
    return seconds_to_time(sec)

def main():
    s = input()
    t = input()
    print(solve(s, t))

if __name__ == '__main__':
    main()