#include <bits/stdc++.h>
using namespace std;
vector<vector<int>> graph;
vector<int> used;
bool dfs(int n) {
  used[n] = 1;
  bool res = true;
  for (int v : graph[n]) {
    if (used[v] == 2) {
      return false;
    }
    if (used[v] == 0) {
      res &= dfs(v);
    }
  }
  return res;
}
int main() {
  int n, m;
  cin >> n >> m;
  vector<vector<int>> field(n, vector<int>(m));
  char c;
  for (int i = 0; i < n; ++i) {
    for (int j = 0; j < m; ++j) {
      cin >> c;
      if (c == '#') {
        field[i][j] = true;
      }
    }
  }
  graph.resize(n + m);
  for (int i = 0; i < n; ++i) {
    for (int j = 0; j < m; ++j) {
      if (field[i][j]) {
        graph[i].push_back(n + j);
        graph[n + j].push_back(i);
      }
    }
  }
  used.resize(n + m);
  for (int i = 0; i < n + m; ++i) {
    if (used[i] == 0) {
      if (!dfs(i)) {
        cout << "No";
        return 0;
      }
      for (int j = 0; j < n; ++j) {
        if (used[j] == 1) {
          for (int k = n; k < n + m; ++k) {
            if (used[k] == 1 && !field[j][k - n]) {
              cout << "No";
              return 0;
            }
          }
          used[j] = 2;
        }
      }
      for (int k = n; k < n + m; ++k) {
        if (used[k] == 1) {
          used[k] = 2;
        }
      }
    }
  }
  cout << "Yes";
  return 0;
}
