#include <bits/stdc++.h>
using namespace std;
string B[101];
int main() {
  int cnt, h, w;
  cin >> h >> w;
  vector<string> s(h);
  for (int i = 0; i < h; i++) cin >> s.at(i);
  for (int y = 0; y < h; y++)
    for (int x = 0; x < w; x++)
      if (s.at(x).at(y) == '#') {
        cnt = 0;
        for (int dx = -1; dx < 2; dx++)
          for (int dy = -1; dy < 2; dy++) {
            if (abs(dx) == abs(dy)) continue;
            int xx = x + dx;
            int yy = y + dy;
            if (0 <= xx && xx < w && 0 <= yy && yy < h)
              if (s.at(xx).at(yy) == '.') cnt++;
          }
        if (cnt == 4) {
          cout << "No" << endl;
          goto OUT;
        }
      }
  cout << "Yes" << endl;
OUT:;
}
