#include <bits/stdc++.h>
//#include <atcoder/all>
using namespace std;
// using namespace atcoder;
// using mint = modint1000000007;
// const int mod = 1000000007;
// using mint = modint998244353;
// const int mod = 998244353;
const int INF = 1e9;
// const long long LINF = 1e18;
#define rep(i, n) for (int i = 0; i < (n); ++i)
#define rep2(i, l, r) for (int i = (l); i < (r); ++i)
#define rrep(i, n) for (int i = (n)-1; i >= 0; --i)
#define rrep2(i, l, r) for (int i = (r)-1; i >= (l); --i)
#define all(x) (x).begin(), (x).end()
#define allR(x) (x).rbegin(), (x).rend()
#define P pair<int, int>
template<typename A, typename B> inline bool chmax(A &a, const B &b) { if (a < b) { a = b; return true; } return false; }
template<typename A, typename B> inline bool chmin(A &a, const B &b) { if (a > b) { a = b; return true; } return false; }

int main() {
	std::ios::sync_with_stdio(false);
	std::cin.tie(nullptr);
	// H+W-2 判定はeasy
	// H+W-1 ???
	// H+W   絶対に行ける
	int h, w; cin >> h >> w;
	vector<string>s(h);
	rep(i, h)cin >> s[i];
	vector dp(h, vector<bool>(w));
	{
		dp[0][0] = true;
		rep(i, h)rep(j, w)if (dp[i][j]) {
			if (i != h - 1) {
				int ni = i + 1;
				int nj = j + 0;
				if (s[ni][nj] != '#')dp[ni][nj] = true;
			}
			if (j != w - 1) {
				int ni = i + 0;
				int nj = j + 1;
				if (s[ni][nj] != '#')dp[ni][nj] = true;
			}
		}
	}
	vector dp2(h, vector<bool>(w));
	{
		dp2[h - 1][w - 1] = true;
		rrep(i, h)rrep(j, w)if (dp2[i][j]) {
			if (i != 0) {
				int ni = i - 1;
				int nj = j + 0;
				if (s[ni][nj] != '#')dp2[ni][nj] = true;
			}
			if (j != 0) {
				int ni = i + 0;
				int nj = j - 1;
				if (s[ni][nj] != '#')dp2[ni][nj] = true;
			}
		}
	}
	if (dp[h - 1][w - 1]) {
		cout << h + w - 2 << endl;
		return 0;
	}
	{
		rep(i, h - 1) {
			int mn = INF;
			int mx = -INF;
			rep(j, w)if (dp[i][j])chmin(mn, j);
			rep(j, w)if (dp2[i + 1][j])chmax(mx, j);
			if (mn <= mx) {
				cout << h + w - 1 << endl;
				return 0;
			}
		}
		rep(j, w - 1) {
			int mn = INF;
			int mx = -INF;
			rep(i, h)if (dp[i][j])chmin(mn, j);
			rep(i, h)if (dp2[i][j + 1])chmax(mx, j);
			if (mn <= mx) {
				cout << h + w - 1 << endl;
				return 0;
			}
		}
	}
	cout << h + w << endl;
	return 0;
}