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())

def dist(X1, Y1, X2, Y2):
	return abs(X1 - X2) + abs(Y1 - Y2)

ans = 10 ** 10
for r in range(R1, R2 + 1):
	for c in range(C1, C2 + 1):
		ans = min(ans, dist(A, B, r, c) + dist(r, c, P, Q) + dist(P, Q, A, B))
print(ans)