#include <bits/stdc++.h>
using namespace std;
const int INF = (int)1e9;
const long long LINF = (long long)1e18;
int n, m;
string s[55];
bool check(int i, int j) {
  if (j - 1 >= 0 && s[i][j - 1] == '#') return 1;
  if (j + 1 < m && s[i][j + 1] == '#') return 1;
  if (i - 1 >= 0 && s[i - 1][j] == '#') return 1;
  if (i + 1 < n && s[i + 1][j] == '#') return 1;
  return 0;
}
int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  ;
  cin >> n >> m;
  for (int i = 0; i < n; i++) cin >> s[i];
  int cnt = 0;
  for (int i = 0; i < n; i++)
    for (int j = 0; j < m; j++)
      if (s[i][j] == '#' && !check(i, j)) cnt++;
  if (cnt == 0)
    cout << "YES";
  else
    cout << "NO";
  return 0;
}
