#include <bits/stdc++.h>

#define ll long long

using namespace std;

ll w, h;

ll sx, sy, ex, ey;

vector<vector<ll>> heights;

vector<pair<ll, bool>> inter;

ll sgn(ll x)
{
    if (x < 0)
        return -1;
    else if (!x)
        return 0;
    return 1;
}

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

    cin >> w >> h;
    cin >> sy >> sx >> ey >> ex;
    heights = vector<vector<ll>>(h / 2, vector<ll>(w / 2));
    for (int i = 0; i < h / 2; i++)
    {
        for (int j = 0; j < w / 2; j++)
        {
            cin >> heights[i][j];
        }
    }

    ll dx = ex - sx;
    ll dy = ey - sy;

    if (dx && dy)
    {
        for (ll i = sy + sgn(dy); i != ey + sgn(dy); i += 2 * sgn(dy))
            inter.push_back({(i - sy) * dx * sgn(dx) * sgn(dy), 0});
        for (ll i = sx + sgn(dx); i != ex + sgn(dx); i += 2 * sgn(dx))
            inter.push_back({(i - sx) * dy * sgn(dx) * sgn(dy), 1});
    }
    else if (dy)
    {
        for (ll i = sy + sgn(dy); i != ey + sgn(dy); i += 2 * sgn(dy))
            inter.push_back({(i - sy) * sgn(dy), 0});
    }
    else
    {
        for (ll i = sx + sgn(dx); i != ex + sgn(dx); i += 2 * sgn(dx))
            inter.push_back({(i - sx) * sgn(dx), 1});
    }
    sort(inter.begin(), inter.end());

    ll x = sx / 2, y = sy / 2;
    ll h = heights[x][y];

    ll ans = 0;

    for (int i = 0; i < inter.size(); i++)
    {
        // cout << inter[i].first << " " << inter[i].second << endl;
        ll newh;
        if (i < inter.size() - 1 && inter[i].first == inter[i + 1].first)
        {
            x += sgn(dx);
            y += sgn(dy);
            newh = heights[x][y];
            ll ma = max(h, newh);
            ma = max(ma, heights[x - sgn(dx)][y]);
            ma = max(ma, heights[x][y - sgn(dy)]);
            ans += abs(ma - h);
            ans += abs(ma - newh);
            i++;
        }
        else if (inter[i].second)
        {
            x += sgn(dx);
            newh = heights[x][y];
            ans += abs(h - newh);
        }
        else
        {
            y += sgn(dy);
            newh = heights[x][y];
            ans += abs(h - newh);
        }
        // cout << h << " " << newh << endl;
        h = newh;
    }
    // cout << ans << endl;
    cout << fixed << setprecision(10) << ans + sqrt(dx * dx + dy * dy) << endl;
    return 0;
}