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.
z=[list(map(int,input().split(':')))for i in range(2)]
a=24-z[1][0]
b=a+z[0][0]
if z[0][1]<z[1][1]:
    b-=1
    d=60-(z[1][1]-z[0][1])
else:
    d=z[0][1]-z[1][1]
if b==24:
    b=0
b='%d'%b    
d='%d'%d
if b<'10':
    b='0'+b
if d<'10':
    d='0'+d
print(b+':'+d)
