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 printtime(a):
    h = a//60
    m = a%60
    if h < 10:
        h = '0' + str(h)
    if m < 10:
        m = '0' + str(m)
    print(h,m, sep = ':')
    
h1,m1 = (int(i) for i in input().split(":"))
h2,m2 = (int(i) for i in input().split(":"))

t1 = h1*60+m1
t2 = h2*60+m2
if t1 >= t2:
    printtime(t1-t2)
else:
    printtime(24*60 - t2 + t1)