#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
ll gcd(ll a, ll b) { return b ? gcd(b, a % b) : a; }
vector<pair<ll, int>> factorize(ll n) {
  vector<pair<ll, int>> res;
  for (ll i = 2; i * i <= n; i++) {
    if (n % i) continue;
    res.emplace_back(i, 0);
    while (n % i == 0) {
      n /= i;
      res.back().second++;
    }
  }
  if (n != 1) res.emplace_back(n, 1);
  return res;
}
ll lcm(ll a, ll b) { return a / gcd(a, b) * b; }
ll ceil(ll a, ll b) { return (a + b - 1) / b; }
const ll INF = LONG_MAX;
template <class T>
inline bool chmax(T &a, T b) {
  if (a < b) {
    a = b;
    return 1;
  }
  return 0;
}
template <class T>
inline bool chmin(T &a, T b) {
  if (a > b) {
    a = b;
    return 1;
  }
  return 0;
}
const int dx[] = {-1, 1, 0, 0};
const int dy[] = {0, 0, -1, 1};
int main() {
  int h, w;
  cin >> h >> w;
  vector<vector<char>> s(h, vector<char>(w, '0'));
  for (int i = 0; i < (int)h; i++) {
    for (int j = 0; j < (int)w; j++) {
      cin >> s[i][j];
    }
  }
  bool is_ok = true;
  for (int i = 0; i < (int)h; i++) {
    for (int j = 0; j < (int)w; j++) {
      bool exist = false;
      for (auto x : dx) {
        for (auto y : dy) {
          int xx = i + x;
          int yy = j + y;
          if (0 <= xx && xx < h) {
            if (0 <= yy && yy < w) {
              if (s[xx][yy] == '#') exist = true;
            }
          }
        }
      }
      if (s[i][j] == '#' && !exist) is_ok = false;
    }
  }
  if (is_ok)
    cout << "Yes";
  else
    cout << "No";
  return 0;
}
