#include <bits/stdc++.h>
using namespace std;
int main() {
  int H, W;
  cin >> H >> W;
  char s[H][W];
  char t[H + 2][W + 2];
  string ANSWER;
  ANSWER = "YES";
  for (int i = 0; i < H; i++) {
    for (int k = 0; k < W; k++) cin >> s[i][k];
  }
  for (int i = 0; i < H + 2; i++) {
    for (int k = 0; k < W + 2; k++) {
      t[i][k] = '.';
    }
  }
  for (int i = 0; i < H; i++) {
    for (int k = 0; k < W; k++) {
      t[i + 1][k + 1] = s[i][k];
    }
  }
  for (int i = 0; i < H; i++) {
    for (int k = 0; k < W; k++) {
      if (t[i + 1][k + 1] == '#' && t[i][k + 1] != '#' && t[i + 1][k] != '#' &&
          t[i + 2][k + 1] != '#' && t[i + 1][k + 2] != '#')
        ANSWER = "NO";
    }
  }
  cout << ANSWER << endl;
  return 0;
}
