#include <bits/stdc++.h>
using namespace std;
int main() {
  int h, w;
  cin >> h >> w;
  vector<string> s(h);
  for (int i = 0; i < h; i++) cin >> s[i];
  for (int i = 0; i < h; i++) {
    for (int j = 0; j < w; j++) {
      if (s[i][j] == '#') {
        bool judge = true;
        if (i != 0) {
          if (j != 0 && s[i - 1][j - 1] == '#') judge = false;
          if (s[i - 1][j] == '#') judge = false;
          if (j != w - 1 && s[i - 1][j + 1] == '#') judge = false;
        }
        if (j != 0 && s[i][j - 1] == '#') judge = false;
        if (j != w - 1 && s[i][j + 1] == '#') judge = false;
        if (i != h - 1) {
          if (j != 0 && s[i + 1][j - 1] == '#') judge = false;
          if (s[i + 1][j] == '#') judge = false;
          if (j != w - 1 && s[i + 1][j + 1] == '#') judge = false;
        }
        if (judge) {
          cout << "No" << endl;
          return 0;
        }
      }
    }
  }
  cout << "Yes" << endl;
  return 0;
}
