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 distance(x1, y1, x2, y2):
    return abs(x1-x2)+abs(y1-y2)

ans = 1<<60
for i in range(R1, R2+1):
    for j in range(C1, C2+1):
        ans = min(ans, distance(A, B, i, j)+distance(i, j, P, Q)+distance(P, Q, A, B))

print(ans)