#include <bits/stdc++.h>
using namespace std;
const int MAXN = 200;
vector<int> g[MAXN], comp;
bool used[MAXN];
set<pair<int, int> > ed;
int n, m;
void dfs(int v) {
  used[v] = true;
  comp.push_back(v);
  for (auto to : g[v]) {
    if (!used[to]) dfs(to);
  }
}
void find_comps() {
  for (int i = 0; i < n + m; ++i) used[i] = false;
  for (int i = 0; i < n + m; ++i)
    if (!used[i]) {
      comp.clear();
      dfs(i);
      for (auto u : comp) {
        for (auto v : comp) {
          if (u < n && v >= n) {
            if (!ed.count(make_pair(u, v))) {
              cout << "No";
              exit(0);
            }
          }
        }
      }
    }
}
int main() {
  ios::sync_with_stdio(false);
  cin >> n >> m;
  char c;
  for (int i = 0; i < n; i++) {
    for (int j = 0; j < m; j++) {
      cin >> c;
      if (c == '#') {
        g[i].push_back(n + j);
        g[n + j].push_back(i);
        ed.insert(make_pair(i, n + j));
      }
    }
  }
  find_comps();
  cout << "Yes";
  return 0;
}
