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()
p = input()
t1 = int(s[len(s) - 2:len(s)]) - int(p[len(p) - 2:len(p)])
k = 0
if t1 < 0:
    t1 += 60
    k = 1
t0 = int(s[:2]) - int(p[:2]) + k
while t0 < 0:
    t0 += 24
t0 %= 24
res = str(t0) + ':'
if len(res) < 3:
    res = '0' + res
ss = '0' + str(t1)
ss = ss[-2:]
res += ss
print(res)