#include <iostream>
#include <iomanip>
#include <vector>
#include <algorithm>
#include <numeric>
#include <functional>
#include <cmath>
#include <queue>
#include <stack>

#define repd(i,a,b) for (int i=(a);i<(b);i++)
#define rep(i,n) repd(i,0,n)
typedef long long ll;

using namespace std;


int inputValue(){
    int a;
    cin >> a;
    return a;
};

void inputArray(int * p, int a){
    rep(i, a){
        cin >> p[i];
    }
};

void inputVector(vector<int> * p, int a){
    rep(i, a){
        int input;
        cin >> input;
        p -> push_back(input);
    }
}

template <typename T>
void output(T a, int precision) {
    if(precision > 0){
        cout << setprecision(precision)  << a << "\n";
    }
    else{
        cout << a << "\n";
    }
}

bool mark[20][20] = {false};
char c[20][20];
int vx[] = {1, -1, 0, 0};
int vy[] = {0, 0, 1, -1};

void dfs(int x, int y){
    mark[x][y] = true;
    rep(i, 4){
        if(mark[x + vx[i]][y + vy[i]] == false && c[x + vx[i]][y + vy[i]] == '.' && x + vx[i] >= 0 && y + vy[i] >= 0){
            dfs(x + vx[i], y + vy[i]);
        }
    }
    
}

int dist(pair<int, int> p, pair<int, int> q){
    return abs(p.first - q.first) + abs(p.second - q.second) - 1;
}

int main(int argc, const char * argv[]) {
    
    // source code
    int width = inputValue();
    int height = inputValue();
    
    
    
    rep(i, height){
        string str;
        cin >> str;
        rep(j, width){
            c[i][j] = str[j];
        }
    }
    
    int start[2] = {0};
    
    // define start
    rep(i, height){
        rep(j, width){
            if(c[i][j] == '.'){
                start[0] = i;
                start[1] = j;
                break;
            }
        }
        if(start[0] != 0 && start[1] != 0) break;
    }
    
    dfs(start[0], start[1]);
    
    vector<pair<int, int>> pos;
    vector<pair<int, int>> neg;
    
    rep(i, height){
        rep(j, width){
            if(mark[i][j] == true){
                pos.push_back(make_pair(i, j));
            }
        }
    }
    rep(i, height){
        rep(j, width){
            if(mark[i][j] == false && c[i][j] == '.'){
                neg.push_back(make_pair(i, j));
            }
        }
    }
    
    int distance = 1000;
    
    rep(p, pos.size()){
        rep(q, neg.size()){
            distance = min(dist(pos[p], neg[q]), distance);
        }
    }
    
    output(distance, 0);
    
    return 0;
}