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()
t = list(map(int, s.split(":")))
h1, m1 = t[0], t[1]

s = input()
t = list(map(int, s.split(":")))

h2, m2 = t[0], t[1]
h = h1-h2
m = m1-m2

if h < 0 and m < 0:
    h = 24+h-1
    m = 60+m


elif h < 0:
    h = 24+h
elif m < 0:
    m = 60+m
    h -= 1
    if h > 23:
        h = 0
print("%02d:%02d" % (h, m,))
