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.
a,b = map(int, input().split(":"))
c, d = map(int, input().split(":"))

a1, a2 = [0]*2

if a < c:
    a1 = a - c + 24
else:
    a1 = a - c
if b< d:
    a2 = b - d + 60
else:
    a2= b - d

a1 = str(a1)
a2 =str(a2)
if len(a1) != 2:
    a1 = "0" + a1
if len(a2) != 2:
    a2 = "0" + a2
print(a1, a2, sep = ":")
