#include <bits/stdc++.h>
using namespace std;
int h, w;
vector<string> s;
bool check(int a, int b) {
  if ((a - 1 < 0) || (b - 1 < 0) || (a + 1 == h) || (b + 1 == w)) return false;
  return true;
}
int main() {
  freopen("input.txt", "r", stdin);
  freopen("output.txt", "w", stdout);
  cin >> h >> w;
  for (int i = 0; i < h; i++) {
    string si;
    cin >> si;
    s.push_back(si);
  }
  for (int i = 0; i < h; i++)
    for (int j = 0; j < w; j++)
      if (check(i, j))
        if ((s[i][j + 1] == '.') && (s[i][j - 1] == '.') &&
            (s[i + 1][j] == '.') && (s[i - 1][j] == '.') && (s[i][j] == '#')) {
          puts("No");
          return 0;
        }
  puts("Yes");
  return 0;
}
