localBackTrack

#include <bits/stdc++.h>
#define     sf      scanf
#define     pf      printf
#define     inf     INT_MAX
#define     dbg     cout << "Debug" << endl;
#define     MAX     1024
#define     block   -1
#define     white   +0
#define     noway   -3
#define     source  -4
#define     goal    -5

using namespace std;

long grid[ MAX ][ MAX ];
int visited[ MAX ][ MAX ];

int dx[] = { +0, -1, +0, +1 };
int dy[] = { -1, +0, +1, +0 };

int sx,sy,gx,gy,l,w,flag = false;

void clr(){
    for( int i=1; i<=l; i++ ){
        for( int j=1; j<=w; j++ ){
            grid[i][j] = visited[i][j] = 0;
        }
    }
    flag = false;
}

bool isOk( int x, int y ){
    return ( x >= 1 && ( x <= l) && y >= 1 && (y<=w) );
}

bool isValid( int mdx, int mdy ){
    if( isOk(mdx,mdy) )
}

bool isNoMove( int x, int y , int pd ){
    for( int i=0; i<4; i++ ){
        int mx = dx[i] + x;
        int my = dy[i] + y;
        if( grid[mx][my] == white && isOk(mx,my)  && isValid(i,pd) ) return false;
    }
    return true;
}


void solve( int x, int y, int pd , int c ){ // was a fuck
    if (grid[x][y] == goal ){
        grid[x][y]=c;
        flag = 1;
        return;
    }

    if ( isNoMove(x,y,pd) ){
        grid[x][y]=noway;
        return;
    }

    for ( int i = 0; i < 4; i++ ){
        int mdx = dx[i] + x;
        int mdy = dy[i] + y;

        if( isOk(mdx,mdy) && !flag && grid[mdx][mdy] <= 0 &&  isValid(mdx,mdy) ){
            solve(mdx,mdy,c+1);
            if( flag )grid[x][y] = c;
            else if( !flag ) grid[x][y] = noway;
        }
    }

}


int main(){
    #ifndef ONLINE_JUDGE
        freopen("in.txt","rt",stdin);
        freopen("out.txt","wt",stdout);
    #endif

    while( sf("%d %d %d %d %d %d", &l,&w,&sx,&sy,&gx,&gy) , l+w+sx+sy+gx+gy ){
        clr();
        grid[sx][sy] = source; grid[gx][gy] = goal;
        for( int i=1; i<=l; i++ ){
            for( int j=1; j<=w; j++ ){
                sf( "%d",&visited[i][j] );
            }
        }

        solve();
    }






    return 0;
}