#include <bits/stdc++.h>
#include <iostream>
#include <vector>
#include <queue>
#include <string>
#include <cstring>
#include <sstream>
#include <set>
#include <map>
#include <algorithm>
#include <cstdio>
#include <cstdlib>

#define rep(i,n) for(int i=0;i<(int)(n);++i)
#define iter(a) __typeof(a.begin())
#define FOR(it,a) for(iter(a)it=a.begin();it!=a.end();++it)
#define F first
#define S second
#define SZ(a) (int)((a).size())
#define sz(a) SZ(a)
#define pb(a) push_back(a)
#define mp(a,b) make_pair(a,b)
#define ALL(a) (a).begin(),(a).end()
using namespace std;

typedef long long ll;
typedef pair<int,int> PI;
typedef unsigned long long ull;

#define PR(...) do{cerr << "line : " << __LINE__ << endl; pr(#__VA_ARGS__, __VA_ARGS__);}while(0);
template<class T>
void pr(const string& name, T t){
  cerr << name << ": " << t << endl;
}

template<typename T, typename ... Types>
void pr(const string& names, T t, Types ... rest) {
  auto comma_pos = names.find(',');
  cerr << names.substr(0, comma_pos) << ": " << t << ", ";
  
  auto next_name_pos = names.find_first_not_of(" \t\n", comma_pos + 1);
  pr(string(names, next_name_pos), rest ...);
}

template<class T,class U> ostream& operator<< (ostream& o, const pair<T,U>& v){return o << "(" << v.F << ", " << v.S << ")";}
template<class T> ostream& operator<< (ostream& o, const vector<T>& v){o << "{";rep(i,SZ(v)) o << (i?", ":"") << v[i];return o << "}";}


#define endl '\n'

string in[110];

int dx[] = {0,1,0,-1};
int dy[] = {-1,0,1,0};


int vis[110][110];

int main(int argc, char *argv[])
{
  ll n,m;
  cin >> n >> m;
  rep(i,n) cin >> in[i];
  
  int fr = 0;
  rep(i,n)rep(j,m) fr += in[i][j]=='.';
  int vcnt = 1;
  rep(i,n)rep(j,m){
    if(in[i][j] == '#') continue;
    //bool fl = i==1 && j == 1;
    rep(k,4){
      ++vcnt;      
      int sdir = k;
      int cx = i + dx[sdir];
      int cy = j + dy[sdir];
      if(cx < 0 || cx >= n || cy < 0 || cy >= m || in[cx][cy] == '#')
        continue;
      
      int cfr = 0;
      do{
        //if(fl) PR(cx,cy);
        ++cfr;
        vis[cx][cy] = vcnt;
        int nx = cx + dx[sdir];
        int ny = cy + dy[sdir];
        if(nx < 0 || nx >= n || ny < 0 || ny >= m ||
           vis[nx][ny] == vcnt || in[nx][ny]=='#') ++sdir;
        sdir &= 3;
        nx = cx + dx[sdir];
        ny = cy + dy[sdir];
        if(nx < 0 || nx >= n || ny < 0 || ny >= m ||
           vis[nx][ny] == vcnt || in[nx][ny]=='#') break;
        cx = nx;
        cy = ny;
        //PR(cx,cy,cfr);
      }while(cx != i || cy != j);
      //PR(cx,cy,cfr);
      
      if(cfr == fr-1 && cx == i && cy == j){
        cout << "YES" << endl;
        return 0;
      }
      //return 0;
    }
  }
  
  cout << "NO" << endl;
}