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=z[0][0]-z[1][0]
b=z[0][1]-z[1][1]
if a<0:
    a+=24
if b<0:
    b+=24       
if a<10:
    a='0'+'%d'%a
if b<10:    
    b='0'+'%d'%b
if type(a) is int:    
     a='%d'%a    
if type(b) is int:     
     a='%d'%b     
print(a+':'+b)