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,b=map(int,input().split(":"))
d,e=map(int,input().split(":"))
if b-e<0 and a-d>0:
    r=a-d-1
    R=60+b-e
elif b-e<0 and a-d==0:
    r=23
    R=60+b-e
elif a-d<0 and b-e>=0:
    r=24+a-d
    R=b-e
elif a-d<0 and b-e<0:
    r=24+a-d
    R=60+b-e
else:
    r=a-d
    R=b-e
r=str(r)
R=str(R)
for i in range(2-len(r)):
    r="0"+r
for i in range(2-len(R)):
    R="0"+R
print(r+":"+R)
    
