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 = input().split(':')
p = input().split(':')

h1, m1 = int(s[0]), int(s[1])
h2, m2 = int(p[0]), int(p[1])

m3 = m1 - m2
h3 = h1 - h2

if m3 < 0:
    h3 -= 1
    m3 += 60

if h3 < 0:
    h3 += 24

if h3 < 10:
    h3 = '0' + str(h3)
else:
    h3 = str(h3)
if m3 < 10:
    m3 = '0' + str(m3)
else:
    m3 = str(m3)

print(h3 + ':' + m3)
