#include<bits/stdc++.h>
using namespace std;
//#pragma GCC optimize("Ofast")

#define rep(i,n) for(ll i=0;i<n;i++)
#define repl(i,l,r) for(ll i=(l);i<(r);i++)
#define per(i,n) for(ll i=(n)-1;i>=0;i--)
#define perl(i,r,l) for(ll i=r-1;i>=l;i--)
#define fi first
#define se second
#define pb push_back
#define ins insert
#define pqueue(x) priority_queue<x,vector<x>,greater<x>>
#define all(x) (x).begin(),(x).end()
#define CST(x) cout<<fixed<<setprecision(x)
#define vtpl(x,y,z) vector<tuple<x,y,z>>
#define rev(x) reverse(x);
using ll=long long;
using vl=vector<ll>;
using vvl=vector<vector<ll>>;
using pl=pair<ll,ll>;
using vpl=vector<pl>;
using vvpl=vector<vpl>;
const ll MOD=1000000007;
const ll MOD9=998244353;
const int inf=1e9+10;
const ll INF=4e18;
const ll dy[9]={1,0,-1,0,1,1,-1,-1,0};
const ll dx[9]={0,1,0,-1,1,-1,1,-1,0};
template<class T> inline bool chmin(T& a, T b) {
    if (a >= b) {
        a = b;
        return true;
    }
    return false;
}
template<class T> inline bool chmax(T& a, T b) {
    if (a < b) {
        a = b;
        return true;
    }
    return false;
}



int main(){
    ll h,w;cin >> h >> w;
    vector<string> g(h);rep(i,h)cin >> g[i];
    {
        vvl mat(h,vl(w));mat[1][1]=1;
        queue<pl> que;que.push({1,1});
        while(que.size()){
            auto [x,y]=que.front();que.pop();
            rep(k,8){
                ll nx=x+dx[k],ny=y+dy[k];
                if(mat[nx][ny])continue;
                bool ok=true;
                rep(l,9){
                    ll nnx=nx+dx[l],nny=ny+dy[l];
                    if(nnx<0||nny<0||nnx>=h||nny>=w){
                        ok=false;break;
                    }
                    if(g[nnx][nny]=='#')ok=false;
                }
                if(ok){
                    que.push({nx,ny});
                    mat[nx][ny]=1;
                }
            }
        }
        if(!mat[h-2][w-2]){
            cout << 0 << endl;return 0;
        }
    }
    rep(i,h){
        rep(j,w){
            if(i<=2&&j<=2)continue;
            if(i>=h-3&&j>=w-3)continue;
            char hoge=g[i][j];
            g[i][j]='#';
            vvl mat(h,vl(w));mat[1][1]=1;
            queue<pl> que;que.push({1,1});
            while(que.size()){
                auto [x,y]=que.front();que.pop();
                rep(k,8){
                    ll nx=x+dx[k],ny=y+dy[k];
                    if(mat[nx][ny])continue;
                    bool ok=true;
                    rep(l,9){
                        ll nnx=nx+dx[l],nny=ny+dy[l];
                        if(nnx<0||nny<0||nnx>=h||nny>=w){
                            ok=false;break;
                        }
                        if(g[nnx][nny]=='#')ok=false;
                    }
                    if(ok){
                        que.push({nx,ny});
                        mat[nx][ny]=1;
                    }
                }
            }
            g[i][j]=hoge;
            if(!mat[h-2][w-2]){
                cout << 1 << endl;return 0;
            }
        }
    }
    cout << 2 << endl;
}