import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.util.Queue;
import java.util.StringTokenizer;

public class Main {

    void solve() throws IOException {
        int h = ni(), w = ni();
        char[][] c = new char[w][h];
        for (int i = 0; i < w; i++) {
            c[i] = ns().toCharArray();
        }

        for (int i = 0; i < w; i++) {
            for (int j = 0; j < h; j++) {
                if (c[i][j] == '.') {
                    boolean[][] used = new boolean[w][h];
                    dfs(c, used, i, j);

                    int ans = Integer.MAX_VALUE;
                    for (int k = 0; k < w; k++) {
                        for (int l = 0; l < h; l++) {
                            for (int m = 0; m < w; m++) {
                                for (int n = 0; n < h; n++) {
                                    if (c[k][l] == '.' && c[m][n] == '.' && used[k][l] && !used[m][n]) {
                                        ans = Math.min(ans, Math.abs(k - m) + Math.abs(l - n) - 1);
                                    }
                                }
                            }
                        }
                    }
                    out.println(ans);
                    return;
                }
            }
        }
    }

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

    void dfs(char[][] c, boolean[][] used, int y, int x) {
        used[y][x] = true;
        for (int i = 0; i < 4; i++) {
            if (c[y + dy[i]][x + dx[i]] == '.' && !used[y + dy[i]][x + dx[i]]) {
                dfs(c, used, y + dy[i], x + dx[i]);
            }
        }
    }

    String ns() throws IOException {
        while (!tok.hasMoreTokens()) {
            tok = new StringTokenizer(in.readLine(), " ");
        }
        return tok.nextToken();
    }

    int ni() throws IOException {
        return Integer.parseInt(ns());
    }

    long nl() throws IOException {
        return Long.parseLong(ns());
    }

    double nd() throws IOException {
        return Double.parseDouble(ns());
    }

    String[] nsa(int n) throws IOException {
        String[] res = new String[n];
        for (int i = 0; i < n; i++) {
            res[i] = ns();
        }
        return res;
    }

    int[] nia(int n) throws IOException {
        int[] res = new int[n];
        for (int i = 0; i < n; i++) {
            res[i] = ni();
        }
        return res;
    }

    long[] nla(int n) throws IOException {
        long[] res = new long[n];
        for (int i = 0; i < n; i++) {
            res[i] = nl();
        }
        return res;
    }

    static BufferedReader in;
    static PrintWriter out;
    static StringTokenizer tok;

    public static void main(String[] args) throws IOException {
        in = new BufferedReader(new InputStreamReader(System.in));
        out = new PrintWriter(System.out);
        tok = new StringTokenizer("");
        Main main = new Main();
        main.solve();
        out.close();
    }
}