INF = 1 << 60

def main():
    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())
    
    ans = INF
    step1 = abs(A - P) + abs(B - Q)
    for r in range(R1, R2 + 1):
        for c in range(C1, C2 + 1):
            step2 = abs(A - r) + abs(P - r) + abs(B - c) + abs(Q - c)
            ans = min(ans, step1 + step2)
    print(ans)

if __name__ == "__main__":
    main()