#include<bits/stdc++.h>
using namespace std;
#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 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 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[8]={0,-1,0,1};
const ll dx[4]={-1,0,1,0};
template <typename T> inline bool chmax(T &a, T b) {
  return ((a < b) ? (a = b, true) : (false));
}
template <typename T> inline bool chmin(T &a, T b) {
  return ((a > b) ? (a = b, true) : (false));
}
ll h,w;
vector<string> ng;
bool ok=false;
void solve(ll x,ll y,ll d){
    ll sx=x,sy=y;
    auto g=ng;
    ll dir=d;
    ll nx=x+dx[dir],ny=y+dy[dir];
    if(nx<0||ny<0||nx>=h||ny>=w)return;
    if(g[x][y]=='#'||g[nx][ny]=='#')return;
    g[nx][ny]='#';x=nx,y=ny;
    while(1){
       // cout << nx <<" " << ny << endl;
        nx=x+dx[dir],ny=y+dy[dir];
        if((nx<0||ny<0||nx>=h||ny>=w)||(g[nx][ny]=='#')){
            dir++;dir%=4;
            nx=x+dx[dir],ny=y+dy[dir];
            if(nx<0||ny<0||nx>=h||ny>=w)break;
            if(g[nx][ny]=='.'){
                g[nx][ny]='#';x=nx,y=ny;continue;
            }
            break;
        }
        else{
            g[nx][ny]='#';x=nx,y=ny;
        }
    }
    if(x!=sx||y!=sy)return;
    bool sss=true;
    rep(i,h)rep(j,w)if(g[i][j]=='.')sss=false;
    ok|=sss;
}
int main(){
  cin >> h >> w;ng.resize(h);rep(i,h)cin >> ng[i];
  rep(i,h){
    rep(j,w){
        rep(k,4){
            solve(i,j,k);
        }
    }
  }
  cout << (ok? "YES":"NO") << endl;

}