using System;
using System.IO;
using System.Linq;
using System.Text;
using System.Diagnostics;
using System.Collections.Generic;
using System.Text.RegularExpressions;
using Enu = System.Linq.Enumerable;

class Program
{
    static readonly int[] DR = { 0, 0, -1, 1 };
    static readonly int[] DC = { -1, 1, 0, 0 };
    int N, InitHP, SX, SY, GX, GY;
    int[][] grid;

    void Solve()
    {
        N = reader.Int();
        InitHP = reader.Int();
        SX = reader.Int() - 1; SY = reader.Int() - 1;
        GX = reader.Int() - 1; GY = reader.Int() - 1;
        grid = reader.IntGrid(N);

        int L = Math.Abs(SX - GX) + Math.Abs(SY - GY) - 1;
        int R = N * N + 1;
        while (R - L > 1)
        {
            int steps = (L + R) / 2;
            if (Reachable(steps)) R = steps;
            else L = steps;
        }
        if (R > N * N) Console.WriteLine(-1);
        else Console.WriteLine(R);
    }

    private bool Reachable(int steps)
    {
        int[,] maxHpAt = new int[N, N];
        maxHpAt[SY, SX] = InitHP;
        var que = new Queue<int>();
        que.Enqueue(SY); que.Enqueue(SX); que.Enqueue(steps);
        Func<int, int, bool> IsInside = (r, c) => r >= 0 && r < N && c >= 0 && c < N;

        while (que.Count > 0)
        {
            int r = que.Dequeue(), c = que.Dequeue();
            int remSteps = que.Dequeue();
            int hp = maxHpAt[r, c];

            for (int d = 0; d < DR.Length; d++)
            {
                int nr = r + DR[d], nc = c + DC[d];
                if (!IsInside(nr, nc)) continue;
                int nextHp = hp - grid[nr][nc];
                int dist = Math.Abs(nr - GY) + Math.Abs(nc - GX);
                if (nextHp > maxHpAt[nr, nc] && dist <= remSteps - 1)
                {
                    if (nr == GY && nc == GX) return true;
                    maxHpAt[nr, nc] = nextHp;
                    que.Enqueue(nr); que.Enqueue(nc); que.Enqueue(remSteps - 1);
                }
            }
        }
        return false;
    }






    Reader reader = new Reader(Console.In);
    static void Main() { new Program().Solve(); }
}

class Reader
{
    private readonly TextReader reader;
    private readonly char[] separator = { ' ' };
    private readonly StringSplitOptions removeOp = StringSplitOptions.RemoveEmptyEntries;
    private string[] A = new string[0];
    private int i;

    public Reader(TextReader r) { reader = r; }
    public bool HasNext() { return Enqueue(); }
    public string String() { return Dequeue(); }
    public int Int() { return int.Parse(Dequeue()); }
    public long Long() { return long.Parse(Dequeue()); }
    public double Double() { return double.Parse(Dequeue()); }
    public int[] IntLine() { var s = Line(); return s == "" ? new int[0] : Array.ConvertAll(Split(s), int.Parse); }
    public int[] IntArray(int N) { return Enu.Range(0, N).Select(i => Int()).ToArray(); }
    public int[][] IntGrid(int H) { return Enu.Range(0, H).Select(i => IntLine()).ToArray(); }
    public string[] StringArray(int N) { return Enu.Range(0, N).Select(i => Line()).ToArray(); }
    public string Line() { return reader.ReadLine().Trim(); }
    private string[] Split(string s) { return s.Split(separator, removeOp); }
    private bool Enqueue()
    {
        if (i < A.Length) return true;
        string line = reader.ReadLine();
        if (line == null) return false;
        if (line == "") return Enqueue();
        A = Split(line);
        i = 0;
        return true;
    }
    private string Dequeue() { Enqueue(); return A[i++]; }
}