#include <bits/stdc++.h>
using namespace std;
int main() {
  int H, W;
  cin >> H >> W;
  vector<vector<int>> data(H, vector<int>(W));
  for (int i = 0; i < H; i++) {
    for (int j = 0; j < W; j++) {
      char a;
      cin >> a;
      if (a == '.')
        data.at(i).at(j) = 0;
      else
        data.at(i).at(j) = -1;
    }
  }
  for (int i = 0; i < H; i++) {
    for (int j = 0; j < W; j++) {
      if (data.at(i).at(j) == -1) {
        bool count = false;
        if (i != 0) {
          if (data.at(i - 1).at(j) == -1) count = true;
        }
        if (i != 0 && j != 0) {
          if (data.at(i - 1).at(j - 1) == -1) count = true;
        }
        if (i != 0 && j != W - 1) {
          if (data.at(i - 1).at(j + 1) == -1) count = true;
        }
        if (j != 0) {
          if (data.at(i).at(j - 1) == -1) count = true;
        }
        if (j != W - 1) {
          if (data.at(i).at(j + 1) == -1) count = true;
        }
        if (i != H - 1) {
          if (data.at(i + 1).at(j) == -1) count = true;
        }
        if (i != H - 1 && j != 0) {
          if (data.at(i + 1).at(j - 1) == -1) count = true;
        }
        if (i != H - 1 && j != W - 1) {
          if (data.at(i + 1).at(j + 1) == -1) count = true;
        }
        if (!count) {
          cout << "No" << endl;
          return 0;
        }
      }
    }
  }
  cout << "Yes" << endl;
}
