#include <bits/stdc++.h>
using namespace std;
int n, m;
string str[150];
bool check(int i, int j) {
  for (int x = 0; x < n; x++) {
    if (str[x][j] == '#') {
      if (str[x] != str[i]) return false;
    }
  }
  return true;
}
int main() {
  cin >> n >> m;
  for (int i = 0; i < n; i++) cin >> str[i];
  for (int i = 0; i < n; i++)
    for (int j = 0; j < m; j++) {
      if (str[i][j] == '#')
        if (!check(i, j)) {
          cout << "No" << endl;
          return 0;
        }
    }
  cout << "Yes" << endl;
  return 0;
}
