#include <bits/stdc++.h>
using namespace std;
int main() {
  int h, w;
  cin >> h >> w;
  string str[h];
  for (int i = 0; i < h; i++) {
    cin >> str[i];
  }
  int dx[8] = {1, 0, -1, 0};
  int dy[8] = {0, 1, 0, -1};
  for (int i = 0; i < h; i++) {
    for (int j = 0; j < w; j++) {
      if (str[i][j] != '.') {
        int num = 0;
        for (int d = 0; d < 8; d++) {
          int ni = i + dy[d];
          int nj = j + dx[d];
          if (ni >= 0 && ni < h) {
            if (nj >= 0 && nj < w) {
              if (str[ni][nj] == '#') num++;
            }
          }
        }
        if (num == 0) {
          cout << "No" << endl;
          return 0;
        }
      }
    }
  }
  cout << "Yes" << endl;
  return 0;
}
