#include <bits/stdc++.h>
using namespace std;
int main() {
  int h, w;
  string data[50][50] = {};
  int cnt = 0;
  cin >> h >> w;
  for (int i = 0; i < h; i++)
    for (int j = 0; j < w; j++) cin >> data[i][j];
  for (int i = 0; i < h; i++) {
    for (int j = 0; j < w; j++) {
      if ((data[i][j + 1] == "#" || data[i][j + 1] == "@") &&
          (data[i][j - 1] == "#" || data[i][j - 1] == "@")) {
        data[i][j + 1] = "@";
        data[i][j - 1] = "@";
      }
      if ((data[i][j + 1] == "#" || data[i][j + 1] == "@") &&
          (data[i + 1][j] == "#" || data[i + 1][j] == "@")) {
        data[i][j + 1] = "@";
        data[i + 1][j] = "@";
      }
      if ((data[i][j + 1] == "#" || data[i][j + 1] == "@") &&
          (data[i - 1][j] == "#" || data[i - 1][j] == "@")) {
        data[i][j + 1] = "@";
        data[i - 1][j] = "@";
      }
      if ((data[i][j - 1] == "#" || data[i][j - 1] == "@") &&
          (data[i - 1][j] == "#" || data[i - 1][j] == "@")) {
        data[i][j - 1] = "@";
        data[i - 1][j] = "@";
      }
      if ((data[i][j + 1] == "#" || data[i][j + 1] == "@") &&
          (data[i - 1][j] == "#" || data[i - 1][j] == "@")) {
        data[i][j + 1] = "@";
        data[i - 1][j] = "@";
      }
      if ((data[i + 1][j] == "#" || data[i + 1][j] == "@") &&
          (data[i - 1][j] == "#" || data[i - 1][j] == "@")) {
        data[i + 1][j] = "@";
        data[i - 1][j] = "@";
      }
    }
  }
  for (int i = 0; i < h; i++) {
    for (int j = 0; j < w; j++) {
      if (data[i][j] == "#") cnt++;
    }
  }
  if (cnt == 0) {
    cout << "Yes";
  } else {
    cout << "No";
  }
}
