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 = list(map(int,input().split(":")))
b = list(map(int,input().split(":")))
h = 0
m = 0
if(a[1]<b[1]):
    a[0] -= 1
    m = 60+a[1]-b[1]
else:
    m = a[1]-b[1]

if(a[0]<b[0]):
    h = 24+a[0]-b[0]
else:
    h = a[0]-b[0]
if(h<10):
    h = "0"+str(h)
if(m<10):
    m = "0"+str(m)
print(str(h)+":"+str(m))