#include <bits/stdc++.h>
using namespace std;
#define PII pair<int,int>
const int mod=167772161;
 
int arr[2000005];
int W,H;

int w(int a, int b)
{
    return a+b*(W+1);
}

struct point
{
    long long x;
    long long y;
};
 
long long ccw(point p1, point p2, point p3)
{
    return (p2.x-p1.x)*(p3.y-p1.y)-(p3.x-p1.x)*(p2.y-p1.y);
}
bool on_seg(point p1, point p2, point p3)
{
    if(p1.x==p2.x)
    {
        if(p1.y<=p2.y&&p2.y<=p3.y)return true;
        if(p1.y>=p2.y&&p2.y>=p3.y)return true;
        return false;
    }
    if(p1.x<=p2.x&&p2.x<=p3.x)return true;
    if(p1.x>=p2.x&&p2.x>=p3.x)return true;
    return false;
}

bool intersect(point p1, point p2, point p3, point p4)
{
    int res=0;
    long long ccw4=ccw(p1,p2,p3);
        long long ccw3=ccw(p1,p2,p4);
        long long ccw2=ccw(p3,p4,p1);
        long long ccw1=ccw(p3,p4,p2);
        if(ccw4==0)
        {
            if(on_seg(p1,p3,p2))return false;
        }
        if(ccw3==0)
        {
            if(on_seg(p1,p4,p2))return false;
        }
        if(ccw2==0)
        {
            if(on_seg(p3,p1,p4))return false;
        }
        if(ccw1==0)
        {
            if(on_seg(p3,p2,p4))return false;
        }
        if(ccw1!=0&&ccw2!=0&&ccw3!=0&&ccw4!=0)
        {
            if(ccw1>=0&&ccw2<=0)res=2;
            else if(ccw1<=0&&ccw2>=0)res=2;
            if(ccw3>=0&&ccw4<=0)res--;
            else if(ccw3<=0&&ccw4>=0)res--;
        }
        
        if(res==1)return true;
        return false;
}
 
 
int main()
{
    ios_base::sync_with_stdio(0);
    long long Sx,Sy,Ex,Ey;
    cin>>W>>H>>Sx>>Sy>>Ex>>Ey;
    double dist=0;
    double dd=(Sx-Ex)*(Sx-Ex)+(Sy-Ey)*(Sy-Ey);
    dist+=sqrt(dd);
    for(int i=0;i<H;i+=2)
    {
        for(int j=0;j<W;j+=2)
        {
            int t;
            cin>>t;
            arr[w(j,i)]=t, arr[w(j+1,i)]=t, arr[w(j,i+1)]=t, arr[w(j+1,i+1)]=t;
        }
    }

    point S={Sx,Sy};
    point E={Ex,Ey};
    for(int i=0;i<H;i++)
    {
        for(int j=1;j<W;j++)
        {
            if(intersect(S,E,{j,i},{j,i+1}))dist+=abs(arr[w(j,i+1)]-arr[w(j,i)]);
        }
    }

    for(int i=0;i<W;i++)
    {
        for(int j=1;j<H;j++)
        {
            if(intersect(S,E,{i,j},{i+1,j}))dist+=abs(arr[w(i+1,j)]-arr[w(i,j)]);
        }
    }
   // cout<<dist<<endl;

    for(int i=1;i<W;i++)for(int j=1;j<H;j++)
    {
        if(Sx==i && Sy==j)continue;
        if(Ex==i && Ey==j)continue;
        if(ccw(S,E,{i,j})==0 && on_seg(S,{i,j},E))
        {
            if(Sx==i)
            {
                int mi1=min(arr[w(i-1,j)],arr[w(i,j)]);
                int mi2=min(arr[w(i,j-1)],arr[w(i-1,j-1)]);
                dist+=abs(mi1-mi2);
            }
            else if(Sy==j)
            {
                int mi1=min(arr[w(i,j-1)],arr[w(i,j)]);
                int mi2=min(arr[w(i-1,j)],arr[w(i-1,j-1)]);
               // cout<<mi1<<" "<<mi2<<" "<<" "<<i<<" "<<j<<endl;
                dist+=abs(mi1-mi2);
            }
            else if(Sx<i)
            {
                int ma1=max(arr[w(i-1,j)],arr[w(i,j-1)]);
                int mi2=min(arr[w(i,j)],arr[w(i-1,j-1)]);
                if(ma1>=mi2)dist+=abs(arr[w(i-1,j)]-arr[w(i,j-1)]);
                else dist+=2*mi2-arr[w(i-1,j)]-arr[w(i,j-1)];
            }
            else if(Sx>i)
            {
                int ma1=max(arr[w(i,j)],arr[w(i-1,j-1)]);
                int mi2=min(arr[w(i-1,j)],arr[w(i,j-1)]);
                if(ma1>=mi2)dist+=abs(arr[w(i,j)]-arr[w(i-1,j-1)]);
                else dist+=2*mi2-arr[w(i,j)]-arr[w(i-1,j-1)];
            }
        }
    }

    cout.precision(10);
    cout<<fixed<<dist<<endl;
}

/*
8 8 1 7 7 7
2 3 2 0
2 1 1 2
1 2 0 0
0 0 0 1
*/