#include <iostream>
#include <queue>
#include <fstream>
#include <vector>
#include <stack>

struct coord{
    unsigned int x, y;
};

void check (std::vector<std::vector<coord>> &last, std::queue<coord> &qu, std::vector<std::vector<char>> &maze, int x, int y, coord &coordinate) {
    last[x][y] = coordinate;
    coord temp;
    temp.x = x;
    temp.y = y;
    qu.push(temp);
    maze[x][y] = '+';
}

int main() {
    unsigned int n, x, y;
    coord start, finish, coordinate;
    std::vector<std::vector<char>> maze;
    std::vector<std::vector<coord>> last;

    std::ifstream inp("input.txt");
    inp >> n >> start.y >> start.x >> finish.x >> finish.y;

    maze.resize(n);
    last.resize(n);
    for (int i = 0; i < n; ++i) {
        maze[i].resize(n);
        last[i].resize(n);
    }

    for (int i = 0; i < n; ++i) {
        for (int j = 0; j < n; ++j) {
            inp >> maze[i][j];
        }
    }
    inp.close();

    start.x--;
    start.y--;
    finish.x--;
    finish.y--;
    std::stack<coord> path;
    std::queue<coord> qu;

    maze[start.x][start.y] = '+';
    coordinate.x = start.x;
    coordinate.y = start.y;
    qu.push(coordinate);

    while (!qu.empty()) {
        coordinate = qu.front();
        x = coordinate.x;
        y = coordinate.y;
        qu.pop();

        if (coordinate.x == finish.y && coordinate.y == finish.x) {
            break;
        }

        if (x > 0 && maze[x - 1][y] == '.') {
            check(last, qu, maze, x-1, y, coordinate);
        }

        if (x < n - 1 && maze[x + 1][y] == '.') {
            check(last, qu, maze, x+1, y, coordinate);
        }

        if (y > 0 && maze[x][y - 1] == '.') {
            check(last, qu, maze, x, y-1, coordinate);
        }

        if (y < n - 1 && maze[x][y + 1] == '.') {
            check(last, qu, maze, x, y+1, coordinate);
        }
    }

    while (coordinate.x != start.x || coordinate.y != start.y) {
        path.push(coordinate);
        coordinate = last[coordinate.x][coordinate.y];
    }
    int res = 0;
    res = path.size();

    std::ofstream outp("output.txt");

    outp << res;
    outp.close();
    return 0;
}