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.
fy = list(map(int, input().split(':')))
ft = list(map(int, input().split(':')))
pf = ps = 0
n = str((fy[0] - ft[0]) % 24)
if int(n) >= 10:
    pf = n
else:
    pf = '0' + n
n = (fy[1] - ft[1])
if n > 0:
    n = str(fy[1] - ft[1])
    if int(n) >= 10:
        ps = n
    else:
        ps = '0' + n

else:
    ps = n % 60
    ps = str(ps)
    pf = str((int(pf) - 1) % 24)
    if len(pf) == 1:
        pf = '0' + pf
print(pf + ':' + ps)