#define _USE_MATH_DEFINES #include <algorithm> #include <cstdio> #include <functional> #include <iostream> #include <cfloat> #include <climits> #include <cstring> #include <cmath> #include <fstream> #include <list> #include <map> #include <queue> #include <set> #include <sstream> #include <stack> #include <string> #include <time.h> #include <vector> using namespace std; typedef long long ll; typedef unsigned long long ull; typedef pair<int, int> i_i; typedef pair<ll, int> ll_i; typedef pair<double, int> d_i; typedef pair<ll, ll> ll_ll; typedef pair<double, double> d_d; struct edge { ll B, T, F, P; }; unsigned MOD = 1000000007; ll _MOD = 1000000009; double EPS = 1e-10; int UNKO = INT_MAX; int dx[] = {-1, 0, 1, 0}; int dy[] = {0, -1, 0, 1}; void dfs(int x, int y, int z, vector<string>& C) { C[y][x] = z; for (int k = 0; k < 4; k++) { int _x = x + dx[k], _y = y + dy[k]; if (C[_y][_x] == '.') dfs(_x, _y, z, C); } } int main() { int W, H; cin >> W >> H; vector<string> C(H); for (int i = 0; i < H; i++) cin >> C[i]; for (int y = 0; y < H; y++) for (int x = 0; x < W; x++) if (C[y][x] == '.') { dfs(x, y, 'A', C); goto unko; } unko:; for (int y = 0; y < H; y++) for (int x = 0; x < W; x++) if (C[y][x] == '.') dfs(x, y, 'B', C); /*for (int y = 0; y < H; y++) cout << C[y] << endl;*/ int mini = INT_MAX; for (int y = 0; y < H; y++) for (int x = 0; x < W; x++) for (int _y = 0; _y < H; _y++) for (int _x = 0; _x < W; _x++) if (C[y][x] == 'A' && C[_y][_x] == 'B') mini = min(mini, abs(x - _x) + abs(y - _y) - 1); cout << mini << endl; }