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.
if __name__ == '__main__':
    h0, m0 = str(input()).split(':')
    h1, m1 = str(input()).split(':')
    h = int(h0) - int(h1)
    m = int(m0) - int(m1)
    if m < 0:
        m += 60
        h -= 1
    if h < 0:
        h += 24
    print('%02d' % h + ':' + '%02d' % m)
