#include <iostream>
#include <string>
#include <algorithm>
#include <vector>
#include <set>
#include <cmath>
#include <iomanip>
#include <stack>
#include <queue>
#include <deque>
#include <bitset>
#include <tuple>
#include <map>
#include <functional>
#include <fstream>
#include <climits>
#include <numeric>
#include <cassert>
//#include <atcoder/all>

#define fi first
#define se second
#define rep(i,n) for(ll i=0;i<(n);i++)
#define rrep(i,n) for(ll i=(n)-1;i>=0;i--)
#define orep(i,n) for(ll i=1;i<=(n);i++)

#define nfor(i,s,n) for(ll i=(s);i<(n);i++)
#define dfor(i,s,n) for(ll i=(s)-1;i>=n;i--)
#define INF 2e18//9223372036854775807

#define all(a)  a.begin(),a.end()
#define rall(a) a.rbegin(),a.rend()

#define chmax(x,y) x = max(x,y)
#define chmin(x,y) x = min(x,y)

#define pb push_back
#define pob pop_back

#define vc vector

#define YES cout << "Yes" << endl;
#define NO cout << "No" << endl;
#define YN {cout << "Yes" << endl;}else{cout << "No" << endl;}
#define dame cout << -1 << endl;

#define vc_unique(v) v.erase(unique(v.begin(), v.end()), v.end())
#define vc_remove(v,x) v.erase(remove(v.begin(), v.end(),x), v.end())
#define vc_rotate(v) rotate(v.begin(), v.begin()+1, v.end())

#define pop_cnt(s) ll(popcount(uint64_t(s)))
#define next_p(v) next_permutation(v.begin(),v.end())

#ifndef ONLINE_JUDGE
#define _GLIBCXX_DEBUG
#endif

using namespace std;
//using namespace atcoder;
using ll = long long;
using ld = long double;
using pll = pair<ll,ll>;
using vvvvvl = vector<vector<vector<vector<vector<ll> > > > >;
using vvvvl = vector<vector<vector<vector<ll> > > >;
using vvvl = vector<vector<vector<ll> > >;
using vvl = vector<vector<ll> >;
using vl = vector<ll>;
using vb = vector<bool>;
using vvb = vector<vector<bool> >;
using Graph = vector<vector<ll> >;

template<class T> using pq = priority_queue<T,vc<T>,less<T> >;
template<class T> using pq_g = priority_queue<T,vc<T>,greater<T> >;

ll dx[4] = {0,1,0,-1};ll ddx[8] = {1,1,0,-1,-1,-1,0,1};
ll dy[4] = {1,0,-1,0};ll ddy[8] = {0,1,1,1,0,-1,-1,-1};

bool out_grid(ll i, ll j, ll h, ll w){//trueならcontinueする
    return(!(0 <= i && i < h && 0 <= j && j<w));
}

ll MOD = 998244353;

ll modpow(ll x,ll y,ll m){
    ll a = x;
    a %= m;
    ll cnt = 0;
    ll ans = 1;
    while(y > 0){
        if((1ll << cnt) & y){
            y ^= (1ll << cnt);
            ans *= a;
            ans %= m;
        }
        a = a*a;
        a %= m;
        cnt++;
    }
    return ans;
}

ll npow(ll x,ll y){
    ll a = x;
    ll cnt = 0;
    ll ans = 1;
    while(y > 0){
        if((1ll << cnt) & y){
            y ^= (1ll << cnt);
            ans *= a;
        }
        a = a*a;
        cnt++;
    }
    return ans;
}

void print(ld x){printf("%.20Lf\n", x);}

////////////////////////////////////////////////////////////////
int main(){
    ll H,W;
    cin >> H >> W;
    vc<vc<char>> G(H,vc<char>(W));
    rep(i,H)rep(j,W)cin >> G[i][j];
    queue<pll> que;
    que.push({0,0});
    vvb seen(H,vb(W,false));
    seen[0][0] = true;

    ll Mx = 0;
    ll My = 0;

    while(!que.empty()){
        auto [x,y] = que.front();
        que.pop();
        rep(i,2){
            ll nx = x + dx[i];
            ll ny = y + dy[i];
            if(out_grid(nx,ny,H,W))continue;
            if(G[nx][ny] == '#')continue;
            if(seen[nx][ny])continue;
            seen[nx][ny] = true;
            chmax(Mx,nx);
            chmax(My,ny);
            que.push({nx,ny});
        }
    }

    if(seen[H-1][W-1]){
        cout << H + W - 2 << endl;
        return 0;
    }

    que.push({H-1,W-1});
    vvb seen2(H,vb(W,false));
    seen2[H-1][W-1] = true;

    ll Mx2 = H-1;
    ll My2 = W-1;

    while(!que.empty()){
        auto [x,y] = que.front();
        que.pop();
        nfor(i,2,4){
            ll nx = x + dx[i];
            ll ny = y + dy[i];
            if(out_grid(nx,ny,H,W))continue;
            if(G[nx][ny] == '#')continue;
            if(seen2[nx][ny])continue;
            seen2[nx][ny] = true;
            chmin(Mx2,nx);
            chmin(My2,ny);
            que.push({nx,ny});
        }
    }

    if(Mx + 1 >= Mx2 || My + 1 >= My2){
        cout << H + W - 1 << endl;
    }else{
        cout << H + W << endl;
    }

    
}