class Program
{
    static (int a, int b) GetInput2()
    {
        int[] input = Console.ReadLine().Split().Select(_ => int.Parse(_)).ToArray();
        return (input[0], input[1]);
    }
    static (int a, int b, int c, int d) GetInput4()
    {
        int[] input = Console.ReadLine().Split().Select(_ => int.Parse(_)).ToArray();
        return (input[0], input[1], input[2], input[3]);
    }

    static void Main()
    {
        (int H, int W) = GetInput2();
        (int sr, int sc) = GetInput2();
        (int r1, int c1, int r2, int c2) = GetInput4();
        (int gr, int gc) = GetInput2();

        int ans = int.MaxValue;
        for (int r = r1; r <= r2; r++)
        {
            for (int c = c1; c <= c2; c++)
            {
                int d = Math.Abs(r - sr) + Math.Abs(c - sc);
                d += Math.Abs(gr - r) + Math.Abs(gc - c);
                d += Math.Abs(sr - gr) + Math.Abs(sc - gc);
                ans = Math.Min(ans, d);
            }
        }
        Console.WriteLine(ans);
    }
}