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.
import math


s=str(input())
s1=str(input())

x=s[0:2]
x1=s[3:len(s)]

y=s1[0:2]
y1=s1[3:len(s1)]

d1=int(x)
d2=int(x1)

d3=int(y)
d4=int(y1)
if(d1==0):
    d1=24
if(d3==0):
    d3=24

m=abs(d1-d3)
n=abs(d4-d2)

gh=str(m)
gm=str(n)

if(len(gh)<2):
    gh1='0'
    gh1+=gh
else:
    gh1=gh
if(len(gm)<2):
    gm1='0'
    gm1+=gm
else:
    gm1=gm
print(gh1+":"+gm1)
