#include<cstdio>
#include<algorithm>
#include<vector>
#include<cmath>
#include<map>

#define S 100007
using namespace std;
typedef long double ld;
typedef long long ll;

vector < int > H[S];


int main(void){
    int w,h;
    int x1,x2,y1,y2;
    scanf("%d %d %d %d %d %d",&w,&h,&x1,&y1,&x2,&y2);
    for(int i = 1; i <= h/2;i++){
        for(int j = 1; j <= w/2;j++){
            int x;
            scanf("%d",&x);
            H[i].push_back(x);
        }
    }
    if(x1 > x2){
        x1 = w - x1;
        x2 = w - x2;
        for(int i = 1; i <= h/2;i++){
            reverse(H[i].begin(),H[i].end());
        }
    }
    if(y1 > y2){
        y1 = h - y1;
        y2 = h - y2;
        for(int i = 1; i <= h/4;i++){
            swap(H[i],H[h/2 - i + 1]);
        }
    }
    int deltaX = abs(x1-x2);
    int deltaY = abs(y1-y2);
    int gcd = __gcd(deltaX,deltaY);
    ld odp = sqrt(deltaX * deltaX + deltaY * deltaY);

    if(x1 == x2 && y1 == y2){

    }else if(x1 == x2){
        for(int i = y1/2+2;i <= y2/2 + 1;i++){
            odp += (ld)abs(H[i][x1/2] - H[i-1][x1/2]);
        }
    }else if(y1 == y2){
        for(int i = x1/2+2;i <= x2/2 + 1;i++){
            odp += (ld)abs(H[y1/2+1][i-1] - H[y1/2+1][i-2]);
        }
    }else{
       //tutaj wszystko :c
       ld a = (ld)(y2-y1) / (ld)(x2-x1);
       ld b = a * (ld)x1 - (ld)y1;
       for(int x = x1+1; x <= x2-1;x+=2){
            ld y = a*(ld)x + b;
            int p = (int)y;
            p /= 2;
            p *= 2;
            if(y - (ld)p < 0.00001 || y - (ld)p > 1.99999)
                continue;
            p++;
            /// (x/2,p/2) -> (x/2+1,p/2)
            odp += abs(H[p/2][x/2-1] - H[p/2][x/2-1]);
       }

       for(int y = y1+1; y <= y2-1;y+=2){
            ld x = ((ld)y - b)/a;
            int p = (int)x;
            p /= 2;
            p *= 2;
            if(x - (ld)p < 0.00001 || x - (ld)p > 1.99999)
                continue;
            p++;
            /// (p/2,y/2) -> (p/2,y/2+1)
            odp += abs(H[y/2][p/2-1] - H[y/2+1][p/2-1]);
       }
       for(int x = x1, y = y1; x != x2 && y != y2; x += deltaX/gcd, y += deltaY/gcd){
            if(x % 2 == 0 && y % 2 == 0){
                ///(x/2,y/2) -> (x/2+1,y/2+1)
                if(H[y/2+1][x/2-1] > H[y/2][x/2-1] && H[y/2][x/2] > H[y/2][x/2-1] &&
                   H[y/2+1][x/2-1] > H[y/2+1][x/2] && H[y/2][x/2] > H[y/2+1][x/2]){
                        odp += (ld)2 * (ld)min(H[y/2+1][x/2-1], H[y/2][x/2]) - (ld)H[y/2][x/2-1] - (ld)H[y/2+1][x/2];
                   }else{
                        odp += (ld)abs(H[y/2][x/2-1] - H[y/2+1][x/2]);
                   }
            }
       }
    }

    printf("%.8Lf",odp);
    return 0;

}