#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
#define rep(i, n) for(ll i = 0; i < (ll)(n); i++)
#define rep2(i, a, n) for(ll i = a; i < (ll)(n); i++)
#define memi cout << endl
#define kono(n) cout << fixed << setprecision(n)
#define all(c) (c).begin(), (c).end()
#define pb push_back
#define hina cout << ' '
#define in(n) cin >> n
#define in2(n, m) cin >> n >> m
#define in3(n, m, l) cin >> n >> m >> l
#define out(n) cout << n
const ll mei = (ll)1e9 + 7;

int main(){
  ll h, w, s;
  s = 0;
  in2(h, w);
  vector<vector<char>> a(h + 2, vector<ll> (w + 2, '.'));
  rep(i, h){
    rep(j, w)
      in(a[i + 1][j + 1]);
  }
  rep(i, h + 2){
    rep(j, w + 2){
      if(a[i][j] == '#' && a[i - 1][j] == '.' && a[i + 1][j] == '.' && a[i][j - 1] == '.' && a[i][j + 1] == '.')
        a++;
    }
  }
  if(a)
    out("No");
  else
    out("Yes");
  memi;
}