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.
def get(s):
    return int(s[:2]) * 60 + int(s[3:5])
def disp(s):
    s = str(s)
    if len(s) == 1:
        s = '0' + s
    print(end = s)
m1 = get(str(input()))
m2 = get(str(input()))
while m2 > 0:
    m1 -= 1
    if m1 == -1:
        m1 = 1439
    m2 -= 1
disp(int(m1 / 60))
print(end = ':')
disp(m1 % 60)
