#include <bits/stdc++.h>
using namespace std;
int main() {
  int a, b;
  cin >> a >> b;
  char d[a + 2][b + 2];
  for (int i = 0; i <= a + 1; i++)
    for (int j = 0; j <= b + 1; j++) d[i][j] = '.';
  for (int i = 1; i <= a; i++)
    for (int j = 1; j <= b; j++) cin >> d[i][j];
  for (int i = 1; i <= a; i++)
    for (int j = 1; j <= b; j++)
      if (d[i][j] == '#' && d[i - 1][j] != '#' && d[i + 1][j] != '#' &&
          d[i][j - 1] != '#' && d[i][j + 1] != '#') {
        cout << "NO";
        return 0;
      }
  cout << "YES";
}
