package No100番台;

import java.util.Scanner;

public class Q157 {
	public static void main(String[] args) throws Exception {
		new Q157().solve();
	}

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

	void dfs(char[][] map, int i, int j, char x) {
		map[i][j] = x;
		for (int k = 0; k < 4; k++) {
			if (map[i + dy[k]][j + dx[k]] == '.')
				dfs(map, i + dy[k], j + dx[k], x);
		}
	}

	void solve() {
		Scanner sc = new Scanner(System.in);
		int w = sc.nextInt();
		int h = sc.nextInt();
		char[][] map = new char[h][w];
		for (int i = 0; i < h; i++) {
			map[i] = sc.next().toCharArray();
		}
		bi: for (int i = 0; i < h; i++) {
			for (int j = 0; j < w; j++) {
				if (map[i][j] == '.') {
					dfs(map, i, j, '1');
					break bi;
				}
			}
		}
		bi: for (int i = 0; i < h; i++) {
			for (int j = 0; j < w; j++) {
				if (map[i][j] == '.') {
					dfs(map, i, j, '2');
					break bi;
				}
			}
		}
		int ans = 999999999;
		for (int i = 0; i < h; i++) {
			for (int j = 0; j < w; j++) {
				if (map[i][j] == '1') {
					for (int k = 0; k < h; k++) {
						for (int l = 0; l < w; l++) {
							if (map[k][l] == '2')
								ans = Math.min(ans, Math.abs(i - k) + Math.abs(j - l));
						}
					}
				}
			}
		}
		System.out.println(ans - 1);
	}
}