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.
t1=list(map(int,input().split(':')))
t2=list(map(int,input().split(':')))
a=(t1[0]-t2[0])%24
b=(t1[1]-t2[1])%60
p=str(a);q=str(b)
if len(p)<2:
    p+='0'
    p=''.join(list(reversed(p)))
if len(q)<2:
    q+='0'
    q=''.join(list(reversed(q)))
print(p+':'+q)