#include <iostream>
#include <vector>
#include <set>
#include <cmath>
#include <iomanip>
using namespace std;

int gcd(int a, int b){
    while(a>0 && b>0){
        if(a>b)
            a %= b;
        else
            b %= a;
    }
    return a+b;
}

int abss(int x){
    return x<0 ? -x : x;
}

int sgn(int x){
    return x<0 ? -1 : 1;
}

int main(){
    ios::sync_with_stdio(false);
    cin.tie(nullptr);

    int w,h,sx,sy,ex,ey;
    cin >> w >> h >> sx >> sy >> ex >> ey;

    vector<vector<int>>H(w/2+1, vector<int>(h/2+1));
    for(int i=1;i<=h/2;i++)
        for(int j=1;j<=w/2;j++)
            cin >> H[j][i];
    
    //process cross-points
    double result = 0.0;
    set<int>UsedX, UsedY;

    int deltaX = ex-sx;
    int deltaY = ey-sy;
    int segs = gcd(abss(deltaX), abss(deltaY));

    if(deltaX!=0 && deltaY!=0)
        for(int i=1;i<segs;i++){
            int x = sx + deltaX/segs*i;
            int y = sy + deltaY/segs*i;
            if(x%2==1 || y%2==1)
                continue;
            // cerr << "Cross x=" << x << " y=" << y << endl;
            
            int main1, main2, aux1, aux2;
            if(sgn(deltaX)==sgn(deltaY)){
                main1 = H[x/2][y/2];
                main2 = H[x/2+1][y/2+1];
                aux1 = H[x/2+1][y/2];
                aux2 = H[x/2][y/2+1];
            }
            else{
                aux1 = H[x/2][y/2];
                aux2 = H[x/2+1][y/2+1];
                main1 = H[x/2+1][y/2];
                main2 = H[x/2][y/2+1];
            }

            int mainUp = max(main1, main2);
            int auxDown = min(aux1, aux2);
            if(auxDown <= mainUp)
                result += abss(main1-main2);
            else
                result += auxDown - main1 + auxDown - main2;
            
            UsedX.insert(x);
            UsedY.insert(y);
        }

    //process rest
    for(int x=sx;x!=ex;x+=sgn(deltaX))
        if(x%2==0 && !UsedX.count(x)){
            // cerr << "Rest x=" << x << endl;
            int y = ((long long)sy*deltaX + (long long)deltaY*(x-sx))/deltaX;
            y -= y%2;
            y += 2;
            y /= 2;

            int h1 = H[x/2][y];
            int h2 = H[x/2+1][y];
            // cerr << "h1=" << h1 << " h2=" << h2 << endl;

            result += abss(h1-h2);
        }
    
    for(int y=sy;y!=ey;y+=sgn(deltaY))
        if(y%2==0 && !UsedY.count(y)){
            // cerr << "Rest y=" << y << endl;
            int x = ((long long)sx*deltaY + (long long)deltaX*(y-sy))/deltaY;
            x -= x%2;
            x += 2;
            x /= 2;

            int h1 = H[x][y/2];
            int h2 = H[x][y/2+1];
            // cerr << "h1=" << h1 << " h2=" << h2 << endl;

            result += abss(h1-h2);
        }

    //output
    cout << fixed << setprecision(6) << result + sqrt((long long)deltaX*deltaX + (long long)deltaY*deltaY) << endl; 

    return 0;
}