#include <iostream>
#include <fstream>
using namespace std;
struct pct
{
    int x,y,pas;
} c[1001];
int dl[]= {-1,0,1,0};
int dc[]= {0,1,0,-1};
ifstream fin("roboti.in");
ofstream fout("roboti.out");
void bordare(int n, int m,int A[][1001])
{
    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 x0, int y0,int A[][1001],int xf, int yf, int&ok )
{
    int u,p;
    p=u=1;
    c[p].x=x0;
    c[p].y=y0;
    c[p].pas=1;
    A[x0][y0]=1;
    while(p<=u)
    {
        pct nc=c[p];
        for(int k=0;k<4;k++)
        {
            if(A[nc.x+dl[k]][nc.y+dc[k]]==0)
            {
                A[nc.x+dl[k]][nc.y+dc[k]]=nc.pas+1;
                u++;
                c[u].x=nc.x+dl[k];
                c[u].y=nc.y+dc[k];
                c[u].pas=nc.pas+1;
                if(c[u].x==xf && c[u].y==yf)
                {
                    fout<<c[u].pas-1;
                    ok=1;
                    p=u+1;
                }
            }

        }
        p++;
    }

}
int n,m,i,j,x0,y0,A[1001][1001],xf,yf,k,ok;
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;
}