#include <iomanip>
#include <iostream>
#include <vector>
#include <math.h>
#include <algorithm>
#include <float.h>

using namespace std;

int main(){
    int w,h,sx,sy,ex,ey;
    cin>>w>>h>>sx>>sy>>ex>>ey;

    vector<vector<int>> t(h,vector<int>(w));
    for(int i=0;i<h/2;i++){
        for(int j=0;j<w/2;j++){
            cin>>t[i][j];
        }
    }

    double d = 0.00000000001;

    double cx=sx, cy=sy;
    double l=0;
    while (true){
        if(sx==ex && sy==ey)break;

        // find next edge
        double nx;
        if (ex > sx) {
            nx = floor(cx/2+1)*2; // ????
        } else {
            nx = ceil(cx/2-1)*2;
        }

        double ny;
        if (ey > sy) {
            ny = floor(cy/2+1)*2;
        } else {
            ny = ceil(cy/2-1)*2;
        }

        // end loop
        if ((nx-sx)/(ex-sx) > 1){
            nx = ex;
        }
        if ((ny-sy)/(ey-sy) > 1){
            ny = ey;
        }

        bool end = false;
        bool xsame = (sx==ex);
        bool ysame = (sy==ey);

        if (!xsame && !ysame && (ey-sy)*(nx-sx) == (ex-sx)*(ny-sy)){

            if (nx == ex || ny == ey) end = true;

            if(!end){
                int a = ((int)ny)/2-1;
                int b = ((int)nx)/2-1;
                int h[4];
                h[0] = t[a][b];
                h[1] = t[a][b+1];
                h[2] = t[a+1][b];
                h[3] = t[a+1][b+1];
                sort(h,h+4);
                int sechig = h[2];
                int sh, eh;
                if ((ex-sx)/(ey-sy) > 0){
                    sh=t[a][b];
                    eh=t[a+1][b+1];
                }else{
                    sh=t[a][b+1];
                    eh=t[a+1][b];
                }
                l+=abs(sechig-sh)+abs(sechig-eh);
            }
        }else if(ysame || (!xsame && (nx-sx)/(ex-sx) < (ny-sy)/(ey-sy))){
            // we move to nx
            ny = sy + (nx-sx)/(ex-sx)*(ey-sy);

            if (!ysame && !xsame && (nx == ex || ny == ey)) end = true;
            if (ysame && nx == ex) end = true;
            if (xsame && ny == ey) end = true;

            if(!end){
                int a = floor(ny/2);
                l+= abs(t[a][((int)nx)/2]-t[a][((int)nx)/2-1]);
            }

        } else {
            // we move to ny
            nx = sx + (ny-sy)/(ey-sy)*(ex-sx);

            if (!ysame && !xsame && (nx == ex || ny == ey)) end = true;
            if (ysame && nx == ex) end = true;
            if (xsame && ny == ey) end = true;

            if(!end){
                int a = floor(nx/2);
                l+= abs(t[((int)ny)/2][a]-t[((int)ny)/2-1][a]);
            }
        }

        l += sqrt((nx-cx)*(nx-cx) + (ny-cy)*(ny-cy));
        cx = nx;
        cy = ny;
        if (end){
            break;
        }
    }

    printf("%f\n",l);
}