#include <bits/stdc++.h>
using namespace std;
long long int mod = 1e18 + 7;
long double eps = 1e-12;
long long int dx[] = {0, 0, 1, -1};
long long int dy[] = {1, -1, 0, 0};
long long int m = 0, n, res = 0, k, h;
long long int gcd(long long int a, long long int b) {
  if (b == 0) return a;
  return gcd(b, a % b);
}
long long int lcm(long long int x, long long int y) {
  return (x * y) / gcd(x, y);
}
string s2, ch = "", s, s1 = "", t;
vector<pair<string, long long int> > vm;
vector<pair<pair<long long int, long long int>, long long int> > vvvl, vvvr;
vector<pair<long long int, long long int> > vv, vv2;
vector<long long int> v[300005];
string a[2000005];
vector<long long int> dp1[2000002], dp2[2000005];
map<pair<long long int, long long int>, long long int> mp;
long long int b[2000005] = {0};
long long int dfs2(long long int x, long long int y, long long int d) {
  mp[{x, y}] = d;
  if (x == (n - 1) && y == (m - 1)) return 1;
  if (x >= n || y >= m) return 0;
  long long int &ret = dp2[x][y];
  if (ret != -1) return ret;
  long long int ans = 0;
  if ((x + 1) < n && a[x + 1][y] == '.') ans |= dfs2(x + 1, y, d + 1);
  if ((y + 1) < m && a[x][y + 1] == '.') ans |= dfs2(x, y + 1, d + 1);
  return ret = ans;
}
long long int dfs1(long long int x, long long int y) {
  if (x == (0) && y == (0)) return 1;
  if (x < 0 || y < 0) return 0;
  long long int &ret = dp1[x][y];
  if (ret != -1) return ret;
  long long int ans = 0;
  if ((x - 1) >= 0 && a[x - 1][y] == '.') ans |= dfs1(x - 1, y);
  if ((y - 1) >= 0 && a[x][y - 1] == '.') ans |= dfs1(x, y - 1);
  return ret = ans;
}
int main() {
  ios_base::sync_with_stdio(0), cin.tie(0), cout.tie(0);
  long long int i = 0, x = 0, z = 0, y = 0, j = 0, q, mx = 0, mm, idx = 0,
                ok = 0, l = 0, r = 0, negatif = 0, positif = 0, l1, r1, g = 0,
                d;
  set<long long int>::iterator it;
  cin >> n >> m;
  for (i = 0; i < n; i++) cin >> a[i];
  for (i = 0; i < n; i++) {
    for (j = 0; j < m; j++) {
      dp1[i].push_back(-1);
      dp2[i].push_back(-1);
    }
  }
  dfs1(n - 1, m - 1);
  dfs2(0, 0, 0);
  if (!dp2[0][0]) return cout << "0", 0;
  for (i = 0; i < n; i++) {
    for (j = 0; j < m; j++) {
      if (i == 0 && j == 0 || i == (n - 1) && j == (m - 1)) continue;
      if (a[i][j] == '#') continue;
      if (dp1[i][j] && dp2[i][j]) {
        b[mp[{i, j}]]++;
      }
    }
  }
  for (i = 0; i <= 2e6; i++) {
    if (b[i] == 1) return cout << "1", 0;
  }
  cout << "2";
  return 0;
}
