#include<bits/stdc++.h>
using namespace std;
using ll=long long;
using pii=pair<int,int>;

#define all(a) a.begin(),a.end()
#define pb push_back
#define sz(a) ((int)a.size())

const int N=2405;
int n,m,b[N][N];
string a[N];
bool vis[N][N];

bool valid(int i, int j){return i>=0&&i<n&&j>=0&&j<m;}

bool bfs(){
    for(int i=0; i<n; ++i) for(int j=0; j<m; ++j) vis[i][j]=0;
    queue<pii> q;
    q.push({1,1}),vis[1][1]=1;
    while(!q.empty()){
        auto [x,y]=q.front(); q.pop();
        for(int i: {-1,0,1}) for(int j: {-1,0,1}){
            int nx=x+i,ny=y+j;
            if(valid(nx,ny)&&b[nx][ny]==0&&!vis[nx][ny]){
                q.push({nx,ny}),vis[nx][ny]=1;
            }
        }
    }
    return vis[n-2][m-2];
}

signed main(){
    ios_base::sync_with_stdio(0),cin.tie(0);
    cin >> n >> m;
    for(int i=0; i<n; ++i) cin >> a[i];
    for(int i=0; i<n; ++i) for(int j=0; j<m; ++j) if(a[i][j]=='#'){
        for(int x: {-1,0,1}) for(int y: {-1,0,1}) if(valid(i+x,j+y)) b[i+x][j+y]++;
    }
    for(int i=0; i<n; ++i) for(int j=0; j<m; ++j) if(i==0||i==n-1||j==0||j==m-1) b[i][j]++;
    if(!bfs()){
        cout << "0\n";
        return 0;
    }
    for(int i=0; i<n; ++i) for(int j=0; j<m; ++j){
        for(int x: {-1,0,1}) for(int y: {-1,0,1}) if(valid(i+x,j+y)) b[i+x][j+y]++;
        if(b[1][1]==0&&b[n-2][m-2]==0&&!bfs()){
            cout << "1\n";
            return 0;
        }
        for(int x: {-1,0,1}) for(int y: {-1,0,1}) if(valid(i+x,j+y)) b[i+x][j+y]--;
    }
    cout << "2\n";
}