#include <bits/stdc++.h>
using namespace std;
using ll=long long;
const ll ILL=2167167167167167167;
const int INF=2100000000;
#define rep(i,a,b) for (int i=(int)(a);i<(int)(b);i++)
#define all(p) p.begin(),p.end()
template<class T> using pq_ = priority_queue<T, vector<T>, greater<T>>;
template<class T> int LB(vector<T> &v,T a){return lower_bound(v.begin(),v.end(),a)-v.begin();}
template<class T> int UB(vector<T> &v,T a){return upper_bound(v.begin(),v.end(),a)-v.begin();}
template<class T> bool chmin(T &a,T b){if(b<a){a=b;return 1;}else return 0;}
template<class T> bool chmax(T &a,T b){if(a<b){a=b;return 1;}else return 0;}
template<class T> void So(vector<T> &v) {sort(v.begin(),v.end());}
template<class T> void Sore(vector<T> &v) {sort(v.begin(),v.end(),[](T x,T y){return x>y;});}
bool yneos(bool a,bool upp=false){if(a){cout<<(upp?"YES\n":"Yes\n");}else{cout<<(upp?"NO\n":"No\n");}return a;}
template<class T> void vec_out(vector<T> &p,int ty=0){
    if(ty==2){cout<<'{';for(int i=0;i<(int)p.size();i++){if(i){cout<<",";}cout<<'"'<<p[i]<<'"';}cout<<"}\n";}
    else{if(ty==1){cout<<p.size()<<"\n";}for(int i=0;i<(int)(p.size());i++){if(i) cout<<" ";cout<<p[i];}cout<<"\n";}}
template<class T> T vec_min(vector<T> &a){assert(!a.empty());T ans=a[0];for(auto &x:a) chmin(ans,x);return ans;}
template<class T> T vec_max(vector<T> &a){assert(!a.empty());T ans=a[0];for(auto &x:a) chmax(ans,x);return ans;}
template<class T> T vec_sum(vector<T> &a){T ans=T(0);for(auto &x:a) ans+=x;return ans;}
int pop_count(long long a){int res=0;while(a){res+=(int)(a&1),a>>=1;}return res;}
template<class T> T square(T a){return a * a;}




void solve();
// DEAR MYSTERIES / TOMOO
int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);

    int t = 1;
    // cin >> t;
    rep(i, 0, t) solve();
}

void solve(){
    int H, W;
    cin >> H >> W;
    vector S(H, vector<char>(W));
    rep(i, 0, H) rep(j, 0, W) {
        cin >> S[i][j];
    }
    int ans = 2;
    rep(rp, 0, 2) {
        {
            vector T(W, vector<char>(H));
            rep(i, 0, H) rep(j, 0, W) {
                T[j][i] = S[i][j];
            }
            swap(H, W);
            swap(S, T);
        }
        vector dp(2, vector<int>(W));
        {
            int ind = 0;
            while (ind != W && S[0][ind] != '#') {
                dp[0][ind] = 1;
                ind++;
            }
        }
        rep(i, 1, H) {
            vector n_dp(2, vector<int>(W));
            rep(k, 0, 2) {
                rep(j, 0, W) if (S[i][j] != '#'){
                    if (dp[k][j]) n_dp[k][j] = 1;
                    if (j != 0 && n_dp[k][j - 1] == 1) n_dp[k][j] = 1;
                }
            }
            {
                int tmp = 0;
                rep(j, 0, W) {
                    if (dp[0][j]) tmp = 1;
                    if (tmp != 0 && S[i][j] != '#') n_dp[1][j] = 1;
                }
            }
            swap(n_dp, dp);
        }
        rep(i, 0, 2) if (dp[i].back()) chmin(ans, i);
    }
    cout << ans + H + W - 2 << "\n";
}
/*
 *
 * 自明な下界 + 2 が達成可能
 * +0 は判定簡単
 * + 1 つまり、1 行入れていけるかを判定すればいい
 *
 */