def main():
    h, w = map(int, input().split())
    a, b = map(int, input().split())
    a -= 1
    b -= 1
    r1, c1, r2, c2 = map(int, input().split())
    r1 -= 1
    c1 -= 1
    r2 -= 1
    c2 -= 1
    p, q = map(int, input().split())
    p -= 1
    q -= 1

    inf = 10**18
    d = [[inf] * w for _ in range(h)]
    for i in range(h):
        for j in range(w):
            if r1 <= i <= r2 and c1 <= j <= c2:
                d[i][j] = abs(a - i) + abs(b - j)

    ans = min(
        abs(p - a) + abs(q - b) + abs(p - i) + abs(q - j) + d[i][j]
        for i in range(h)
        for j in range(w)
    )
    print(ans)


if __name__ == "__main__":
    main()