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(":")))
if a[1]<b[1]:
    a[0]-=1
    a[1]+=60
if a[0]<b[0]:
    a[0]+=24
x=str(a[0]-b[0])
y=str(a[1]-b[1])
if len(x)==1:
    x="0"+x
if len(y)==1:
    y="0"+y
print(x+":"+y)