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 = list(map(int, input().split(':')))
t = list(map(int, input().split(':')))

p = [0, 0]
if s[0] - t[0] < 0:
    p[0] = 24 - (t[0] - s[0])
else:
    p[0] = s[0] - t[0]

if s[1] - t[1] < 0:
    p[1] = 60 - (t[1] - s[1])
    if s[0] == 0:
        p[0] = 23
    else:
        p[0] -= 1
else:
    p[1] = s[1] - t[1]

if p[0] < 10:
    print('0', p[0], sep = '', end = ':')
else:
    print(p[0], end = ':')
if p[1] < 10:
    print('0', p[1], sep = '')
else:
    print(p[1])
