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())

a = 9223372036854775807
pos = (-1, -1)
for i in range(r1, r2+1):
	for j in range(c1, c2+1):
		if a > abs(i-A)+abs(j-B):
			a = abs(i-A)+abs(j-B)
			pos = (i,j)
print(a+abs(pos[0]-P)+abs(pos[1]-Q)+abs(P-A)+abs(Q-B))