#include <bits/stdc++.h>

using namespace std;

#define ALL(x) (x).begin(), (x).end()

template<class C> void mini(C &a5, C b5) { a5 = min(a5, b5); }
template<class C> void maxi(C &a5, C b5) { a5 = max(a5, b5); }

#ifdef LOCAL
const bool debug = true;
#else
const bool debug = false;
#define cerr if (true) {} else cout
#endif

#define int long long
#define double long double

const int INF = 1e18;
const int mod = 1e9 + 7;

const int nax = 100010;

#define kwa(a) ((a) * (a))

int ilo(const pair<int, int> &a, pair<int, int> b, pair<int, int> c) {
	b.first -= a.first; b.second -= a.second;
	c.first -= a.first; c.second -= a.second;
	return b.first * c.second - c.first * b.second; 
}

vector<int> height[nax];
vector<bool> czy[nax];

pair<int, int> s, e;

bool is_int(int x, int y) {
	bool a = s.first <= x && x <= e.first;
	bool b = e.first <= x && x <= s.first;
	bool c = s.second <= y && y <= e.second;
	bool d = e.second <= y && y <= s.second;
	return (a || b) && (c || d);
}

bool prz_lin(pair<int, int> a, pair<int, int> b) {
	int x = ilo(s, e, a);
	int y = ilo(s, e, b);
	return  (x > 0 && y < 0) || 
			(x < 0 && y > 0);
}

bool prz_pro(int x, int y) {
	if (!is_int(x, y)) return false;
	return prz_lin({2 * x, 2 * y}, {2 * x - 2, 2 * y - 2}) ||
		   prz_lin({2 * x, 2 * y - 2}, {2 * x - 2, 2 * y});
}

int foo(int x, int y) {
	if (!czy[x][y]) return 0;
	
	int res = 0;
	
	for (int i = -1; i <= 1; i++) {
		for (int j = -1; j <= 1; j++) {
			if (i == 0 && j == 0) continue;
			int x2 = x + i;
			int y2 = y + j;
			
			if (i * j == 0) {
				if (czy[x2][y2]) {
					res += abs(height[x][y] - height[x2][y2]); 
				}
			}
		}
	}
	
	return res;
}

int rog_na_wysokosc(int x, int y) {
	x /= 2;
	y /= 2;
	vector<int> v {
		height[x][y],
		height[x + 1][y],
		height[x][y + 1],
		height[x + 1][y + 1]
	};
	sort(ALL(v));
	
	int res = 0;
	for (int i = 0; i <= 1; i++) {
		for (int j = 0; j <= 1; j++) {
			if (czy[i + x][j + y])
				res += abs(v[2] - height[i + x][j + y]);
		}
	}
	return res;
}

int32_t main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    
    int w, h;
    cin >> w >> h >> s.first >> s.second >> e.first >> e.second;
    
    for (int i = 0; i <= h + 5; i++) {
		height[i].resize(w + 10);
		czy[i].resize(w + 10);
	}
    
    for (int i = 1; i <= h/2; i++) {
		for (int j = 1; j <= w/2; j++) {
			cin >> height[i][j];
			czy[i][j] = prz_pro(i, j);
		}
	}
	czy[s.first][s.second] = true;
	czy[e.first][e.second] = true;
	
	if (debug) {
		for (int i = 1; i <= h/2; i++) {
			for (int j = 1; j <= w/2; j++) {
				cerr << czy[i][j];
			}
			cerr << endl;
		}
	}
	
	double res = sqrt(kwa(s.first - e.first) + kwa(s.second - e.second));
	int ad = 0;
    for (int i = 1; i <= h/2; i++) {
		for (int j = 1; j <= w/2; j++) {
			ad += foo(i, j);
		}
	}
	
	for (int i = 0; i <= h; i+=2) {
		for (int j = 0; j <= w; j+=2) {
			if (is_int(i, j) && ilo(s, e, {i, j}) == 0) {
				ad += rog_na_wysokosc(i, j);
				cerr << i << " " << j << " " << ad << endl;
			}
		}
	}
	
	cerr << ad << endl;
	cout << fixed << setprecision(10) << res + ad << "\n";
    
    return 0;
}/*
8 8 1 7 7 1
2 3 2 0
2 1 1 2
1 2 0 0
0 0 0 1
*/