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.
h1 , m1 = map(int, input().split(":")) 
h2 , m2 = map(int, input().split(":")) 

h = h1 - h2
m = m1 - m2
if h < 0:
    h = 24 + h
if m < 0:
    m = 60 + m

h = str(h)
m = str(m)
if len(h) == 1:
    h = "0" + h
if len(m) == 1:
    m = "0" + m

print(h + ":" + m)