#include <bits/stdc++.h>
using namespace std;
int main(void) {
  int H, W;
  cin >> H >> W;
  int s[W + 1][H + 1];
  for (int i = 1; i <= H; i++) {
    for (int j = 1; j <= W; j++) cin >> s[j][i];
  }
  for (int i = 1; i <= H; i++) {
    for (int j = 1; j <= W; j++) {
      if (s[j][i] == '#') {
        if (s[j - 1][i - 1] != '#' && s[j - 1][i + 1] != '#' &&
            s[j + 1][i - 1] != '#' && s[j + 1][i + 1] != '#') {
          cout << "No";
          return 0;
        }
      }
    }
  }
  cout << "Yes";
  return 0;
}
