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(":")
t = input().split(":")

h = int(s[0]) - int(t[0])

m = int(s[1]) - int(t[1])
while m < 0:
    m += 60
    h -= 1
while h < 0:
    h += 24


mstr = ''
if m < 10:
    mstr = '0' + str(m)
else:
    mstr = str(m)

hstr = ''
if h < 10:
    hstr = '0' + str(h)
else:
    hstr = str(h)

print(hstr + ':' + mstr)

