#include <bits/stdc++.h>
using namespace std;
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
inline long long int rand(long long int x, long long int y) {
  ++y;
  return (rng() % (y - x)) + x;
}
string to_string(char c) {
  string second(1, c);
  return second;
}
string to_string(bool b) { return (b ? "true" : "false"); }
template <typename A, typename B>
string to_string(pair<A, B> p) {
  return "(" + to_string(p.first) + ", " + to_string(p.second) + ")";
}
template <typename A>
string to_string(A v) {
  bool first = true;
  string res = "{";
  for (const auto &x : v) {
    if (!first) {
      res += ", ";
    }
    first = false;
    res += to_string(x);
  }
  res += "}";
  return res;
}
void degug_out() { cerr << endl; }
template <typename Head, typename... Tail>
void degug_out(Head H, Tail... T) {
  cerr << " " << to_string(H);
  degug_out(T...);
}
inline long long int gcd(long long int a, long long int b) {
  if (a > b) swap(a, b);
  if (a == 0) return b;
  return gcd(b % a, a);
}
long long int n, m;
vector<vector<char>> grid;
vector<vector<int>> dist, dist2;
long long int dx[] = {1, 0, -1, 0};
long long int dy[] = {0, 1, 0, -1};
void bfs(long long int x, long long int y, long long int op) {
  dist[x][y] = 0;
  queue<pair<long long int, long long int>> q;
  q.emplace(x, y);
  while (q.size()) {
    long long int x = q.front().first, y = q.front().second;
    q.pop();
    if (op == 0) {
      for (long long int i = (0); i <= (long long int)(1); ++i) {
        long long int nx = x + dx[i];
        long long int ny = y + dy[i];
        if (nx < 0 || ny < 0 || nx >= n || ny >= m || ~dist[nx][ny] ||
            grid[nx][ny] == '#')
          continue;
        dist[nx][ny] = dist[x][y] + 1;
        q.emplace(nx, ny);
      }
    } else {
      for (long long int i = (2); i <= (long long int)(3); ++i) {
        long long int nx = x + dx[i];
        long long int ny = y + dy[i];
        if (nx < 0 || ny < 0 || nx >= n || ny >= m || ~dist[nx][ny] ||
            grid[nx][ny] == '#')
          continue;
        dist[nx][ny] = dist[x][y] + 1;
        q.emplace(nx, ny);
      }
    }
  }
  return;
}
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  cin >> n >> m;
  grid.resize(n, vector<char>(m, '*'));
  dist.resize(n, vector<int>(m, -1));
  dist2.resize(n, vector<int>(m, -1));
  for (long long int i = (0); i <= (long long int)(n - 1); ++i)
    for (long long int j = (0); j <= (long long int)(m - 1); ++j)
      cin >> grid[i][j];
  bfs(0, 0, 0);
  swap(dist, dist2);
  bfs(n - 1, m - 1, 1);
  if (dist2[n - 1][m - 1] == -1) {
    cout << 0;
    return 0;
  }
  map<long long int, long long int> co;
  for (long long int i = (0); i <= (long long int)(n - 1); ++i)
    for (long long int j = (0); j <= (long long int)(m - 1); ++j)
      if (~dist[i][j] && ~dist2[i][j] && dist2[i][j] &&
          dist2[i][j] != (n - 1 + m - 1))
        co[dist2[i][j]]++;
  for (long long int i = (0); i <= (long long int)(n - 1); ++i)
    for (long long int j = (0); j <= (long long int)(m - 1); ++j)
      if (~dist[i][j] && ~dist2[i][j] && dist2[i][j] &&
          dist2[i][j] != (n - 1 + m - 1))
        if (co[dist2[i][j]] == 1) {
          cout << 1;
          return 0;
        }
  cout << 2;
}
