#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
#define rep(i,n) for(int i=0;i<(int)(n);i++)
#define rep1(i,n) for(int i=1;i<=(int)(n);i++)
#define fs first
#define sc second
typedef vector<ll> vl;
typedef vector<int> vi;
typedef vector<string> vs;
typedef vector<char> vc;
typedef vector<tuple<ll,ll>> vtl;
typedef pair<ll, ll> l_l;
#define EPS (1e-7)
#define INF (1e9)
#define PI (acos(-1))

void solve(){
    //abc96c
    int h,w;
    cin>>h>>w;
    string board[60];
    rep(i,h)cin>>board[i];
    int dx[]={1,0,-1,0};
    int dy[]={0,1,0,-1};
    bool f=0;
    int cnt=0;
    rep(i,h){
        rep(j,w){
            if(board[i][j]=='#'){
                rep(k,4){
                    int x=i+dx[k];
                    int y=j+dy[k];
                    if(x>=0&&x<h&&y>=0&&y<w&&board[x][y]=='#')f=1;
                    else cnt++;
                    if(cnt==4){
                        cout<<"No"<<endl;
                        return;
                    }
                }
            }
        }
    }
    if(h==1&&w==1&&board[0][0]=='#'){
        cout<<"Yes"<<endl;
        return;
    }
    cout<<(f?"Yes":"No")<<endl;
}