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.
h, m = [int(x) for x in input().split(':')]
h_del, m_del = [int(x) for x in input().split(':')]

if m - m_del < 0:
    h = (h - 1) % 24
m = (m - m_del) % 60
h = (h - h_del) % 24

m = str(m)
h = str(h)

if len(m) == 1:
    m = '0' + m
if len(h) == 1:
    h = '0' + h

print(h + ':' + m)
