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.
n = [int(k) for k in input().split(':')]
m = [int(k) for k in input().split(':')]
k = n[0]*60 + n[1]
j = m[0]*60 + m[1]
def h(x):
    for s in range(2 - len(x)):
        x = str(0) + x
    return x
def f(x):
    a = int(x/60)
    b = x%60
    c = h(str(a))+':'+h(str(b))
    return c
if k >= j:
    print(f(k-j))
else:
    print(f(k+24*60-j))