#include<bits/stdc++.h>
#include<atcoder/all>
using namespace std;
using namespace atcoder;
typedef long long int ll;
typedef long double ld;
typedef vector<ll> vi;
typedef vector<vi> vvi;
typedef vector<vvi> vvvi;
typedef vector<vvvi> vvvvi;
typedef vector<bool> vb;
typedef vector<vb> vvb;
typedef vector<vvb> vvvb;
typedef vector<vvvb> vvvvb;
typedef pair<ll,ll> pi;
typedef pair<ll,pi> ppi;
typedef pair<ll,ppi> pppi;
typedef pair<ll,pppi> ppppi;
#define FOR(i,l,r) for(ll i=l;i<r;i++)
#define REP(i,n) FOR(i,0,n)
#define RFOR(i,l,r) for(ll i=r-1;i>=l;i--)
#define RREP(i,n) RFOR(i,0,n)
#define ALL(x) x.begin(),x.end()
#define F first
#define S second
#define BS(A,x) binary_search(ALL(A),x)
#define LB(A,x) (ll)(lower_bound(ALL(A),x)-A.begin())
#define UB(A,x) (ll)(upper_bound(ALL(A),x)-A.begin())
#define COU(A,x) (UB(A,x)-LB(A,x))
#define sz(c) ((ll)(c).size())
/*
#include<boost/multiprecision/cpp_int.hpp>
namespace mp=boost::multiprecision;
using Bint=mp::cpp_int;
*/
template<typename T>using min_priority_queue=priority_queue<T,vector<T>,greater<T>>;
template<typename T1,typename T2>ostream&operator<<(ostream&os,pair<T1,T2>&p){os<<p.F<<" "<<p.S;return os;}
template<typename T1,typename T2>istream&operator>>(istream&is,pair<T1,T2>&p){is>>p.F>>p.S;return is;}
template<typename T>ostream&operator<<(ostream&os,vector<T>&v){REP(i,sz(v))os<<v[i]<<(i+1!=sz(v)?" ":"");return os;}
template<typename T>istream&operator>>(istream&is,vector<T>&v){for(T&in:v)is>>in;return is;}
template<class T>bool chmax(T&a,T b){if(a<b){a=b;return 1;}return 0;}
template<class T>bool chmin(T&a,T b){if(b<a){a=b;return 1;}return 0;}
ld dist(ld x1,ld y1,ld x2,ld y2){return sqrtl((x1-x2)*(x1-x2)+(y1-y2)*(y1-y2));}
vi fast_mod_convolution(vi&a,vi&b,ll mod){
  const ll m1=167772161,m2=469762049,m3=1224736769;
  const ll m1_inv_m2=inv_mod(m1,m2);
  const ll m12_inv_m3=inv_mod(m1*m2,m3);
  const ll m12_mod=m1*m2%mod;
  auto x=convolution<m1>(a,b);
  auto y=convolution<m2>(a,b);
  auto z=convolution<m3>(a,b);
  vector<ll>ret(sz(a)+sz(b)-1);
  REP(i,sz(ret)){
    ll v1=(y[i]-x[i])*m1_inv_m2%m2;if(v1<0)v1+=m2;
    ll v2=(z[i]-(x[i]+m1*v1)%m3)*m12_inv_m3%m3;if(v2<0)v2+=m3;
  	ret[i]=(x[i]+m1*v1+m12_mod*v2)%mod;
  }
  return ret;
}
const ld EPS=1e-8;
//*
using mint=modint998244353;
const ll mod=998244353;
//*/
/*
using mint=modint1000000007;
const ll mod=1000000007;
//*/
//using mint=modint;
//*
typedef vector<mint> vm;
typedef vector<vm> vvm;
typedef vector<vvm> vvvm;
typedef vector<vvvm> vvvvm;
ostream&operator<<(ostream&os,mint&a){os<<a.val();return os;}
//*/
int main(){
  ll H,W;cin>>H>>W;
  vector<string>S(H);cin>>S;
  vvi X(H+W-1),Y(H+W-1);
  REP(i,H)REP(j,W)if(S[i][j]=='.'){
  	X[i+j].emplace_back(i+W-1-j);
  	Y[i+W-1-j].emplace_back(i+j);
  }
  vvi T(H,vi(W));
  REP(i,H)REP(j,W)if(S[i][j]=='#'){
  	T[i][j]=min({i,H-1-i,j,W-1-j});
  	{
  		ll t=LB(X[i+j],i+W-1-j);
  		if(t<sz(X[i+j]))chmin(T[i][j],(X[i+j][t]-(i+W-1-j))/2-1);
  		if(t)chmin(T[i][j],((i+W-1-j)-X[i+j][t-1])/2-1);
  	}
  	{
  		ll t=LB(Y[i+W-1-j],i+j);
  		if(t<sz(Y[i+W-1-j]))chmin(T[i][j],(Y[i+W-1-j][t]-(i+j))/2-1);
  		if(t)chmin(T[i][j],((i+j)-Y[i+W-1-j][t-1])/2-1);
  	}
  }
  //REP(i,H)cout<<T[i]<<endl;
  vvi P(H+1,vi(W+1)),Q(H+1,vi(W+1));
  REP(i,H)REP(j,W)if(S[i][j]=='#'&&T[i][j]){
  	P[i-T[i][j]][j-T[i][j]]++;
  	P[i+T[i][j]+1][j+T[i][j]+1]--;
  	Q[i-T[i][j]][j+T[i][j]]++;
  	if(j>T[i][j])Q[i+T[i][j]+1][j-T[i][j]-1]--;
  }
  REP(i,H)REP(j,W)P[i+1][j+1]+=P[i][j];
  REP(i,H)REP(j,W)Q[i+1][j]+=Q[i][j+1];
  REP(i,H)REP(j,W)if(S[i][j]=='#'&&P[i][j]+Q[i][j]==0){cout<<"No"<<endl;return 0;}
  cout<<"Yes"<<endl;
  return 0;
}