#include <bits/stdc++.h>
   
using namespace std;
 
typedef long long int ll;
typedef long double ld;

ifstream fin("car.in");
ofstream fout("car.out");

const int INF = 1e9;
const int dx[] = {-1, -1, -1, 0, 1, 1, 1, 0};
const int dy[] = {-1, 0, 1, 1, 1, 0, -1, -1};

vector < vector < int > > road;
vector < vector < int > > dist[8];

struct var {
    int dir, x, y, dist;

    var (int _dir, int _x, int _y, int _dist): dir(_dir), x(_x), y(_y), dist(_dist) {};
    bool operator < (const var &other) const {
        return ((this -> dist) < other.dist);
    }
};

int main() {
    int n, m; fin >> n >> m;
    int bx, by, ex, ey;
    fin >> bx >> by >> ex >> ey;
    --bx; --by; --ex; --ey;

    road.resize(n);
    for (auto &x: road) x.resize(m);
    for (int i = 0; i < n; ++i) {
        for (int j = 0; j < m; ++j) {
            fin >> road[i][j];
        }
    }
    if (road[bx][by] == 1 || road[ex][ey] == 1) {
        fout << "-1";
        exit(0);
    }

    for (auto &y: dist) {
        y.resize(n);
        for (auto &x: y) {
            x.resize(m, INF);
        }
    }

    priority_queue < var > Set;
    for (int d = 0; d < 8; ++d) {
        dist[d][bx][by] = 0;
        Set.push({d, bx, by, 0});
    }

    while(!Set.empty()) {
        auto tmp = Set.top();
        int dir = tmp.dir;
        int x = tmp.x;
        int y = tmp.y;
        int len = tmp.dist;
        Set.pop();

        if(dist[dir][x][y] != len) continue;
        for (int way = 0; way < 8; ++way) {
            int nx = x + dx[way];
            int ny = y + dy[way];

            if(nx < 0 || ny < 0 || nx >= n || ny >= m || road[nx][ny] == 1) continue;

            int cost = len + abs(way - dir);
            if (cost < dist[way][nx][ny]) {
                dist[way][nx][ny] = cost;
                Set.push({way, nx, ny, cost});
            }
        }
    }

    int mn = INF;
    for (int i = 0; i < 8; ++i) {
        mn = min(mn, dist[i][ex][ey]);
    }

    if(mn == INF) {
        fout << "-1";
    } else {
        fout << mn;
    }
    return 0;
}