#include <bits/stdc++.h>

using namespace std;

typedef pair<int, int> P;

string field[20];
int W, H;

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

void dfs(int x, int y, vector<P>& p) {
    if (field[y][x] == '#') return;
    p.emplace_back(P(x, y));
    field[y][x] = '#';
    for (int i = 0; i < 4; i++) {
        int w = x + dx[i], h = y + dy[i];
        if (w < 0 || w >= W || h < 0 || h >= H) continue;
        dfs(w, h, p);
    }
    return;
}

int main() {
    cin.tie(0);
    ios::sync_with_stdio(false);
    cin >> W >> H;
    for (int i = 0; i < H; i++) cin >> field[i];
    vector<P> a, b;
    bool flag = false;
    for (int i = 0; i < H; i++) {
        for (int j = 0; j < W; j++) {
            if (field[i][j] == '.') {
                dfs(j, i, a);
                flag = true;
                break;
            }
        }
        if (flag) break;
    }
    flag = false;
    for (int i = 0; i < H; i++) {
        for (int j = 0; j < W; j++) {
            if (field[i][j] == '.') {
                dfs(j, i, b);
                flag = true;
                break;
            }
        }
        if (flag) break;
    }
    int ans = 1000;
    for (unsigned int i = 0; i < a.size(); i++) {
        for (unsigned int j = 0; j < b.size(); j++) {
            int dis = abs(a[i].first - b[j].first) + abs(a[i].second - b[j].second) - 1;
            ans = min(ans, dis);
        }
    }
    cout << ans << "\n";
    return 0;
}