#include <bits/stdc++.h>
using namespace std;
using ll = long long;
int main() {
  int h, w;
  cin >> h >> w;
  char s[h + 2][w + 2];
  fill(s[0], s[w + 2], '.');
  for (int i = 0; i < (h); ++i)
    for (int j = 0; j < (w); ++j) cin >> s[i + 1][j + 1];
  for (int i = 0; i < (h); ++i) {
    for (int j = 0; j < (w); ++j) {
      bool flag = false;
      if (s[i + 1][j + 1] == '#') {
        for (int k = (-1); k < (2); ++k) {
          for (int l = (-1); l < (2); ++l) {
            if (k != 0 && l != 0)
              if (s[i + 1 + k][j + 1 + l] == '#') {
                flag = true;
              }
          }
        }
        if (!flag) {
          cout << "Yes" << endl;
          return 0;
        }
      }
    }
  }
  cout << "No" << endl;
  return 0;
}
