#include <bits/stdc++.h>

using namespace std;

#define inf INT_MAX
#define mp make_pair
#define f first
#define s second
class InParser
{
private:
    FILE *fin;
    char *buff;
    int sp;

    char read_ch()
    {
        ++sp;
        if (sp == 4096)
        {
            sp = 0;
            fread(buff, 1, 4096, fin);
        }
        return buff[sp];
    }

public:
    InParser(const char* nume)
    {
        fin = fopen(nume, "r");
        buff = new char[4096]();
        sp = 4095;
    }

    InParser& operator >> (int &n)
    {
        char c;
        while (!isdigit(c = read_ch()) && c != '-');
        int sgn = 1;
        if (c == '-')
        {
            n = 0;
            sgn = -1;
        }
        else
        {
            n = c - '0';
        }
        while (isdigit(c = read_ch()))
        {
            n = 10 * n + c - '0';
        }
        n *= sgn;
        return *this;
    }

    InParser& operator >> (long long &n)
    {
        char c;
        n = 0;
        while (!isdigit(c = read_ch()) && c != '-');
        long long sgn = 1;
        if (c == '-')
        {
            n = 0;
            sgn = -1;
        }
        else
        {
            n = c - '0';
        }
        while (isdigit(c = read_ch()))
        {
            n = 10 * n + c - '0';
        }
        n *= sgn;
        return *this;
    }
};
InParser fin("car.in");
ofstream fout("car.out");
const int N=509;
int vx[]= {-1,-1,0,1,1,1,0,-1},vy[]= {0,1,1,1,0,-1,-1,-1},a[N][N],d[8][N][N];
int n,m,xi,yi,xf,yf,i,j;
queue <pair<int,pair<int,int> > > q,Q;
void bordare()
{
    for(int i=0; i<=n+1; i++)
    {
        a[i][0]=a[i][m+1]=1;
    }
    for(int i=0; i<=m+1; i++)
    {
        a[0][i]=a[n+1][i]=1;

    }
}
void read()
{
    fin>>n>>m;
    fin>>xi>>yi>>xf>>yf;
    for(i=1; i<=n; i++)
        for(j=1; j<=m; j++)
            fin>>a[i][j];
}
void solve()
{
    bordare();
    for(int p=0; p<8; p++)
        for(i=1; i<=n; i++)
            for(j=1; j<=m; j++)
                d[p][i][j]=inf;
    for(int i=0; i<8; i++)
        if(!a[xi+vx[i]][yi+vy[i]])
            q.push(mp(i,mp(xi+vx[i],yi+vy[i]))),d[i][xi+vx[i]][yi+vy[i]]=0;
    while(!q.empty())
    {
        while(!q.empty())
        {
            int dir,x,y;
            int DIR=q.front().f;
            int X=q.front().s.f;
            int Y=q.front().s.s;
            q.pop();
            dir=DIR,x=X+vx[dir],y=Y+vy[dir];
            if(!a[x][y]&&d[dir][x][y]>d[DIR][X][Y])
            {
                d[dir][x][y]=d[DIR][X][Y];
                q.push(mp(dir,mp(x,y)));
            }
            dir=(DIR+1)%8,x=X,y=Y;
            if(d[dir][x][y]>d[DIR][X][Y]+1)
            {
                d[dir][x][y]=d[DIR][X][Y]+1;
                Q.push(mp(dir,mp(x,y)));
            }
            dir=(DIR+7)%8,x=X,y=Y;
            if(d[dir][x][y]>d[DIR][X][Y]+1)
            {
                d[dir][x][y]=d[DIR][X][Y]+1;
                Q.push(mp(dir,mp(x,y)));
            }
        }
        while(!Q.empty())
        {
            q.push(Q.front());
            Q.pop();
        }
    }
    int ans=inf;
    for(int i=0; i<8; i++)
        ans=min(ans,d[i][xf][yf]);
    if(ans==inf)
        fout<<-1;
    else
        fout<<ans;
}
int main()
{
    read();
    solve();
    return 0;
}