#include <bits/stdc++.h>
using namespace std;
int main() {
  int h, w;
  cin >> h >> w;
  string grid[h + 2];
  string tmbh = "";
  for (int i = 0; i <= w + 1; i++) {
    tmbh = tmbh + '.';
  }
  grid[0] = tmbh;
  grid[h + 1] = tmbh;
  for (int i = 1; i <= h; i++) {
    string a;
    cin >> a;
    a = '.' + a + '.';
    grid[i] = a;
  }
  bool bisa = true;
  for (int i = 1; i <= h; i++) {
    for (int j = 1; j <= w; j++) {
      bool ini = true;
      if (grid[i][j] == '#') {
        ini = false;
        if (grid[i][j + 1] == '#') {
          ini = true;
        }
        if (grid[i][j - 1] == '#') {
          ini = true;
        }
        if (grid[i + 1][j] == '#') {
          ini = true;
        }
        if (grid[i - 1][j] == '#') {
          ini = true;
        }
      }
      if (!ini) {
        bisa = false;
        cout << i << " " << j << endl;
        break;
      }
    }
  }
  if (bisa) {
    cout << "Yes" << endl;
  } else {
    cout << "No" << endl;
  }
  return 0;
}
