#include <bits/stdc++.h>
using namespace std;
long long a[200][200];
long long rr[200];
long long cc[200];
int main() {
  int n, m;
  cin >> n >> m;
  for (int i = 0; i < n; i++)
    for (int j = 0; j < m; j++) {
      char c;
      cin >> c;
      a[i][j] = (c == '#');
      rr[i] = rr[i] * 2 + a[i][j];
      cc[j] = cc[j] * 2 + a[i][j];
    }
  bool ok = true;
  for (int row = 0; row < n; row++) {
    long long s = -1;
    for (int j = 0; j < m; j++) {
      if (a[row][j]) {
        if (s != -1 && s != cc[j]) ok = false;
        s = cc[j];
      }
    }
  }
  for (int col = 0; col < m; col++) {
    long long s = -1;
    for (int i = 0; i < n; i++) {
      if (a[i][col]) {
        if (s != -1 && s != rr[i]) ok = false;
        s = rr[i];
      }
    }
  }
  cout << (ok ? "Yes" : "No") << endl;
}
