#include <fstream>
#include <queue>
#include <vector>
#include <bitset>
#include <cmath>
#pragma warning(disable:4996)

using namespace std;

const int NMAX = 505;
const int oo = 0x3f3f3f3f;
bitset <NMAX> a[NMAX];

struct car
{
	int x, y, c, dir;
};

int cost[8][NMAX][NMAX], mini = oo;

queue<car> q1, q2;

class InParser
{
private:
	FILE* fin;
	char* buff;
	int sp;
	char read()
	{
		++sp;
		if (sp == 4096)
		{
			sp = 0;
			fread(buff, 1, 4096, fin);
		}
		return buff[sp];
	}
public:
	InParser(const char* nume)
	{
		sp = 4095;
		fin = fopen(nume, "r");
		buff = new char[4096];
	}
	InParser& operator >> (int& n)
	{
		char c;
		while (!isdigit(c = read()));
		n = c - '0';
		while (isdigit(c = read()))
			n = n * 10 + c - '0';
		return *this;
	}
};

InParser fin("car.in");
ofstream fout("car.out");

int n, m, t, sx, sy, fx, fy;

int dx[] = { -1, -1, 0, 1, 1, 1, 0, -1 };
int dy[] = { 0, 1, 1, 1, 0, -1, -1, -1 };

inline bool ok(car b)
{
	return b.x && b.y && b.x <= n && b.y <= m && a[b.x][b.y] == 0;
}

int solve()
{
	car u, v;
	for (int i = 0; i < 8; ++i)
		q1.push({ sx, sy, 0, i });
	while (!q1.empty())
	{
		while (!q1.empty())
		{
			u = q1.front();
			q1.pop();
			v = u;
			v.x += dx[v.dir];
			v.y += dy[v.dir];
			if (ok(v) && cost[v.dir][v.x][v.y] > v.c)
			{
				q1.push(v);
				cost[v.dir][v.x][v.y] = v.c;
			}
			v = u;
			++v.c;
			++v.dir;
			if (v.dir == 8)
				v.dir = 0;
			if (ok(v) && cost[v.dir][v.x][v.y] > v.c)
			{
				q2.push(v);
				cost[v.dir][v.x][v.y] = v.c;
			}
			v.dir = u.dir - 1;
			if (v.dir < 0)
				v.dir = 7;
			if (ok(v) && cost[v.dir][v.x][v.y] > v.c)
			{
				q2.push(v);
				cost[v.dir][v.x][v.y] = v.c;
			}
		}
		while (!q2.empty())
		{
			q1.push(q2.front());
			q2.pop();
		}
	}
	for (int i = 0; i < 8; ++i)
		if (cost[i][fx][fy] < mini)
			mini = cost[i][fx][fy];
	if (mini == oo) mini = -1;
	return mini;
}

int main()
{
	fin >> n >> m;
	fin >> sx >> sy >> fx >> fy;
	for (int i = 1; i <= n; ++i)
		for (int j = 1; j <= m; ++j)
		{
			fin >> t;
			a[i][j] = t;
			for (t = 0; t < 8; ++t)
				cost[t][i][j] = oo;
		}

	if (a[sx][sy] == 1 || a[fx][fy] == 1)
	{
		fout << "-1\n";
		return 0;
	}

	for (int i = 0; i < 8; ++i)
		cost[i][sx][sy] = 0;

	fout << solve() << "\n";

	return 0;
}