#include <bits/stdc++.h>
using namespace std;
using lli = long long;
using ld = long double;
inline void Solve() {
  int n = 0, m = 0;
  cin >> n >> m;
  vector<vector<char>> data(n, vector<char>(m));
  for (int i = 0; i < n; i++)
    for (int j = 0; j < m; j++) cin >> data[i][j];
  for (int i = 0; i < n; i++) {
    set<int> line, row;
    for (int j = 0; j < m; j++) {
      if (data[i][j] == '#') {
        line.insert(i);
        row.insert(j);
        for (int t = 0; t < n; t++) {
          if (data[t][j] == '#') {
            line.insert(t);
          }
        }
      }
    }
    for (auto it : line) {
      for (int j = 0; j < m; j++) {
        if ((data[it][j] == '#') && (row.count(j) == 0)) {
          cout << "No";
          return;
        }
      }
    }
    for (auto it : row) {
      for (int t = 0; t < n; t++) {
        if ((data[t][it] == '#') && (line.count(t) == 0)) {
          cout << "No";
          return;
        }
      }
    }
  }
  cout << "Yes";
}
signed main() {
  cout << fixed << setprecision(20);
  Solve();
  return 0;
}
