#include <iostream>
#include <queue>
#include <tuple>
using namespace std;

#define REP(i,a,b) for(int i=a;i<(int)b;i++)
#define rep(i,n) REP(i,0,n)

typedef long long ll;

int W, H;
char G[22][22];
int F[22][22];
bool vis[22][22];

int dx[4] = {-1,0,1,0};
int dy[4] = {0,-1,0,1};

inline bool valid(int x, int y) {
  return 0<=x&&x<W && 0<=y&&y<H;
}

inline bool balid(int x, int y) {
  return G[y][x] == '.';
}

void bfs(int x, int y, int key) {
  std::queue<std::pair<int, int>> q;
  q.emplace(x, y);
  vis[y][x] = 1;
  while(!q.empty()) {
    F[y][x] = key;
    x = q.front().first, y = q.front().second;
    q.pop();
    rep(k, 4) {
      int nx = x+dx[k], ny = y+dy[k];
      if(!valid(nx, ny) || !balid(nx, ny)) { continue; }
      if(vis[ny][nx]) { continue; }
      vis[y][x] = 1;
      q.emplace(nx, ny);
    }
  }
}

int main() {

  cin >> W >> H;
  rep(i, H) rep(j, W) {
    cin >> G[i][j];
  }

  int key = 1;
  rep(i, H) rep(j, W) {
    if(G[i][j] == '.' && F[i][j] == 0) {
      bfs(j, i, key++);
    }
  }

  int ans = 1<<29;
  rep(i, H) rep(j, W) {
    if(F[i][j] == 1) {
      rep(k, H) rep(l, W) {
        if(F[k][l] == 2) {
          ans = min(ans, abs(k-i)+abs(l-j)-1);
        }
      }
    }
  }

  cout << ans << endl;

  return 0;
}