H, W = (int(x) for x in input().split())
A, B = (int(x) - 1 for x in input().split())
li, lj, ri, rj = (int(x) for x in input().split())
li, lj = li - 1, lj - 1
P, Q = (int(x) - 1 for x in input().split())

result = (H + W) * 3
for i in range(li, ri):
    for j in range(lj, rj):
        result = min(result, abs(A - i) + abs(i - P) + abs(P - A) + abs(B - j) + abs(j - Q) + abs(Q - B))
print(result)