#include<iostream>
#include<vector>
#include<queue>

using namespace std;

int main() {
	int n = 0, m = 0, x0 = 0, y0 = 0, x1 = 0, y1 = 0;
	cin >> n >> m;
	vector<vector<int> > v(n, vector<int>(m, n * m));
	for (int i = 0; i < n; i++)
	{
		for (int j = 0; j < m; j++)
		{
			int x;
			cin >> x;
			if (x != 0)
				v[i][j] = -1;

		}
	}
	cin >> x0 >> y0 >> x1 >> y1;
	x0--; y0--; x1--; y1--;
	v[y0][x0] = 0;
	queue<pair<int, int> > q;
	q.push({ y0, x0 });
	while (!q.empty()) {
		int y = q.front().first;
		int x = q.front().second;
		q.pop();
		if (x - 1 >= 0 && v[y][x] + 1 < v[y][x -1] && v[y][x -1] != -1) {
			v[y][x-1] = v[y][x] + 1;
			q.push({ y,x - 1 });
		}
		if (x + 1 < m && v[y][x] + 1 < v[y][x + 1] && v[y ][x + 1] != -1) {
			v[y][x + 1] = v[y][x] + 1;
			q.push({y, x + 1});
		}
		if (y - 1 >= 0 && v[y][x] + 1 < v[y - 1][x] && v[y - 1][x] != -1) {
			v[y -1][x] = v[y][x] + 1;
			q.push({ y - 1 ,x});
		}
		if (y + 1 < n && v[y][x] + 1 < v[y + 1][x] && v[y + 1][x] != -1) {
			v[y + 1][x] = v[y][x] + 1;
			q.push({  y + 1,x });
		}
	}
	if (v[y1][x1] == m * n || v[y1][x1] == -1)
		cout << -1;
	else
		cout << v[y1][x1];
	return 0;
}