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

typedef struct Pct {
    int x;
    int y;
    int pas;
} Pct;

Pct c[1000000], pi, pf;
int n,m,i,j,x0,y0,A[1002][1002],xf,yf,k,ok;
int dl[]= {-1,0,1,0},
    dc[]= {0,1,0,-1};

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

void bordare (int n, int m,int A[1002][1002])
{
    for(int i=0; i<=n+1; i++)
    {
        A[0][i]=-1;
        A[n+1][i]=-1;
    }
    for(int i=0; i<=m+1; i++)
    {
        A[i][0]=-1;
        A[i][m+1]=-1;
    }
}

void lee(int xi, int yi,int A[1002][1002],int xf, int yf, int &ok )
{
    int u = 0,p = 0;
    bool exit = false;

    c[p].x=xi;
    c[p].y=yi;
    c[p].pas=1;

    A[xi][yi]=1;

    while(p<=u && !exit)
    {
        for(int k=0; k<4; k++)
        {
            if(A[c[p].x+dl[k]][c[p].y+dc[k]]==0)
            {
                u++;

                c[u].x=c[p].x+dl[k];
                c[u].y=c[p].y+dc[k];
                c[u].pas=c[p].pas+1;

                A[c[u].x][c[u].y]=c[u].pas;

                if(c[u].x==xf && c[u].y==yf)
                {
                    fout<<c[u].pas-1;
                    ok=1;
                    exit = true;
                    break;
                }
            }

        }

        p++;
    }

}

int main()
{
    fin>>n>>m;

    for(i=1; i<=n; i++) {
        for(j=1; j<=m; j++)
        {
            fin>>A[i][j];
            if(A[i][j]==1)
                A[i][j]=-1;
        }
    }

    fin>>x0>>y0;

    fin>>xf>>yf;

    ok=0;
    bordare(n,m,A);
    lee(x0,y0,A,xf,yf,ok);
    if(ok==0)
        fout<<-1;

    return 0;
}