#include <bits/stdc++.h>
using namespace std;
int main() {
  cin.tie(0);
  ios::sync_with_stdio(false);
  int H, W;
  cin >> H >> W;
  vector<string> board(H);
  for (int i = 0; i < H; i++) cin >> board[i];
  const int dx[4] = {-1, 1, 0, 0};
  const int dy[4] = {0, 0, -1, 1};
  bool can = true;
  for (int i = 0; i < H; i++)
    for (int j = 0; j < W; j++) {
      if (board[i][j] == '.') continue;
      bool can2 = false;
      for (int d = 0; d < 8; d++) {
        int ni = i + dx[d];
        int nj = j + dy[d];
        if (ni < 0 || ni >= H) continue;
        if (nj < 0 || nj >= W) continue;
        if (board[ni][nj] == '#') {
          can2 = true;
          break;
        }
      }
      if (can2) {
      } else {
        can = false;
        break;
      }
    }
  if (can)
    cout << "Yes"
         << "\n";
  else
    cout << "No"
         << "\n";
  return 0;
}
