#include <iostream>
#include <fstream>
#include <vector>
using namespace std;

ifstream in("in.txt");
ofstream out("out.txt");
int n, m, i_begin, j_begin, i_end, j_end;
vector <vector<int>> matrix;

void solve(int i, int j, int temp) {
    matrix[i][j] = temp;
    if (matrix[i][j] != -1) {
        if (matrix[i + 1][j + 2] > temp + 1 || matrix[i + 1][j + 2] == 0) solve(i + 1, j + 2, temp + 1);
        if (matrix[i - 1][j + 2] > temp + 1 || matrix[i - 1][j + 2] == 0) solve(i - 1, j + 2, temp + 1);
        if (matrix[i + 1][j - 2] > temp + 1 || matrix[i + 1][j - 2] == 0) solve(i + 1, j - 2, temp + 1);
        if (matrix[i - 1][j - 2] > temp + 1 || matrix[i - 1][j - 2] == 0) solve(i - 1, j - 2, temp + 1);
        if (matrix[i + 2][j + 1] > temp + 1 || matrix[i + 2][j + 1] == 0) solve(i + 2, j + 1, temp + 1);
        if (matrix[i - 2][j + 1] > temp + 1 || matrix[i - 2][j + 1] == 0) solve(i - 2, j + 1, temp + 1);
        if (matrix[i + 2][j - 1] > temp + 1 || matrix[i + 2][j - 1] == 0) solve(i + 2, j - 1, temp + 1);
        if (matrix[i - 2][j - 1] > temp + 1 || matrix[i - 2][j - 1] == 0) solve(i - 2, j - 1, temp + 1);
    }
}

int main() {

    in >> n;
    in >> m;
    matrix.resize(n + 4, vector <int>(m + 4, -1));
    int n_temp = n + 2, m_temp = m + 2;
    for (size_t i = 2; i < n_temp; i++) {
        for (size_t j = 2; j < m_temp; j++) {
            in >> matrix[i][j];
        }
    }
    in >> i_begin;
    in >> j_begin;
    in >> i_end;
    in >> j_end;
    if (i_begin == i_end && j_begin == j_end) {
        out << "0";
        return 0;
    }

    solve(i_begin + 1, j_begin + 1, 0);
    matrix[i_end + 1][j_end + 1] > 0 ? out << matrix[i_end + 1][j_end + 1] : out << "No";

    return 0;
}