#include<bits/stdc++.h>
using namespace std;

int h, w;
string c[2000];

int main() {
    cin >> h >> w;
    for(int i = 0; i < h; i++){
        cin >> c[i];
    }
    vector<vector<bool>> dpS(h, vector<bool>(w, 0));
    dpS[0][0] = 1;
    for(int i = 0; i < h; i++){
        for(int j = 0; j < w; j++){
            if(c[i][j] == '#'){
                dpS[i][j] = 0; continue;
            }
            if(i > 0 && dpS[i-1][j]) dpS[i][j] = 1;
            if(j > 0 && dpS[i][j-1]) dpS[i][j] = 1;
        }
    }
    vector<vector<bool>> dpG(h, vector<bool>(w, 0));
    dpG[h - 1][w - 1] = 1;
    for(int i = h - 1; i >= 0; i--){
        for(int j = w - 1; j >= 0; j--){
            if(c[i][j] == '#'){ 
                dpG[i][j] = 0; continue;
            }
            if(i < h - 1 && dpG[i + 1][j]) dpG[i][j] = 1;
            if(j < w - 1 && dpG[i][j + 1]) dpG[i][j] = 1;
        }
    }

    if(dpS[h - 1][w - 1]){
        cout << h + w - 2 << "\n";
        return 0;
    }
    bool isok = 0;
    for(int i = 0; i < h - 1; i++){
        bool pref = 0;
        for(int j = 0; j < w; j++){
            if(dpS[i][j]) pref = 1; 
            if(pref && dpG[i + 1][j]) isok = 1; 
        }
    }
    for(int j = 0; j < w - 1; j++){
        bool pref = 0;
        for(int i = 0; i < h; i++){
            if(dpS[i][j]) pref = 1;
            if(pref && dpG[i][j + 1]) isok = 1;
        }
    }
    if(isok){
        cout << h + w - 1 << "\n";
    }
    else {
        cout << h + w << "\n";
    }
}