h,w=map(int,input().split())
a,b=map(int,input().split())
r1,c1,r2,c2=map(int,input().split())
p,q=map(int,input().split())
ans=10**18
for i in range(r1,r2+1):
	for j in range(c1,c2+1):
		ans=min(ans,abs(i-a)+abs(j-b)+abs(i-p)+abs(j-q)+abs(a-p)+abs(b-q))
print(ans)