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(str,input().split(":"))
c,d = map(str,input().split(":"))
a = int(a)
b = int(b)
c = int(c)
d = int(d)
f = a-c
l = b-d
if f < 0:
    f = 24 + f
if l < 0:
    l = 60 - l
    f -= 1
if f < 10:
    f = str(f)
    f = "0"+f
if l < 10:
    l = str(l)
    l = "0" + l
print(f,end = ":")
print(l)