#include <bits/stdc++.h>
using namespace std;
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  int h, w;
  cin >> h >> w;
  char a[100][100];
  for (int i = 1; i <= h; i++) {
    for (int j = 1; j <= w; j++) cin >> a[i][j];
  }
  for (int i = 0; i <= h + 1; i++) {
    a[i][0] = '.';
    a[i][w + 1] = '.';
  }
  for (int j = 0; j <= w + 1; j++) {
    a[0][j] = '.';
    a[h + 1][j] = '.';
  }
  for (int i = 1; i <= h; i++) {
    for (int j = 1; j <= w; j++) {
      if (a[i][j] == '#') {
        if (a[i][j - 1] == '#' || a[i][j + 1] == '#' || a[i + 1][j] == '#' ||
            a[i - 1][j] == '#')
          continue;
        else {
          cout << "NO";
          return 0;
        }
      }
    }
  }
  cout << "YES";
}
