#include <fstream>
using namespace std;
ifstream in("car.in");
ofstream out("car.out");

const int nmax = 506;
int a[nmax][nmax], b[nmax][nmax], n, m, x1, x2, y11, y2, rasp;
int q[2][8 * nmax * nmax];

int dir[8][2]={{0, 1},
{1, 1},
{1, 0},
{1, -1},
{0, -1},
{-1, -1},
{-1, 0},
{-1, 1}};

int cod(int x, int y, int dir)
{
    return (((x<<9)+y)<<3)+dir;
}

struct str{
    int x, y, dir;
};

str deco(int a)
{
    str s;
    s.dir = a & 7;
    a >>= 3;
    s.y = a & 511;
    a >>= 9;
    s.x = a;
    return s;
}

inline bool on_map(int x, int y)
{
    if(!x || !y || x>n || y>m)
        return 0;
    return 1;
}

int main()
{
    int player_unu=0;

    in>>n>>m;
    in>>x1>>y11>>x2>>y2;
    if(x1==x2 && y11==y2)
    {
        out << "0\n";
        return 0;
    }

    for(int i = 1; i<=n; i++)
    {
        for(int j = 1; j<=m; j++)
        {
            in>>a[i][j];
        }
    }

    for(int i = 0; i<=7; i++)
    {
        q[0][++q[0][0]] = cod(x1, y11, i);
    }

    for(int i = 0; !b[x2][y2] && q[i&1][0]; i++, rasp++)
    {
        while(q[i&1][0])
        {
            int nod = q[i&1][q[i&1][0]];

            q[i&1][0]--;
            str s = deco(nod);
            if((b[s.x][s.y]&(1<<s.dir)))
               continue;

            b[s.x][s.y] += (1<<s.dir);
            s.x += dir[s.dir][0];
            s.y += dir[s.dir][1];

            if(on_map(s.x, s.y) && !a[s.x][s.y] && !(b[s.x][s.y]&(1<<s.dir)))
            {
                q[i&1][++q[i&1][0]] = cod(s.x, s.y, s.dir);
            }

            s.x -= dir[s.dir][0];
            s.y -= dir[s.dir][1];

            for(int j =- 1; j<=1; j+=2)
            {
                s.dir += j + 8;
                s.dir &= 7;
                if(!(b[s.x][s.y]&(1<<s.dir)))
                {
                    q[(i+1)&1][++q[(i+1)&1][0]] = cod(s.x, s.y, s.dir);
                }

                s.dir = s.dir - j + 8;
                s.dir &= 7;
            }
        }
    }

    if(!b[x2][y2])
        rasp = 0;
    out<<rasp - 1<<"\n";

    return player_unu;
}