#include <bits/stdc++.h>
using namespace std;
bool isOK(string s[], int i, int j, int H, int W) {
  bool ret = false;
  if (s[i][j] == '.') return true;
  if (i != 0 && s[i - 1][j] == '#') {
    ret = true;
  }
  if (j != 0 && s[i][j - 1] == '#') {
    ret = true;
  }
  if (i != W - 1 && s[i + 1][j] == '#') {
    ret = true;
  }
  if (j != W - 1 && s[i][j + 1] == '#') {
    ret = true;
  }
  cout << i << " " << j << " ret=" << ret << endl;
  return ret;
}
int main() {
  int H, W;
  cin >> H >> W;
  string s[100];
  for (int i = 0; i < H; ++i) cin >> s[i];
  string ans = "Yes";
  for (int i = 0; i < H; i++) {
    for (int j = 0; j < W; j++) {
      if (!isOK(s, i, j, H, W)) {
        ans = "No";
      }
    }
  }
  cout << (ans) << endl;
  ;
}
