#include <bits/stdc++.h>
using namespace std;
void dfs(int s, vector<vector<int>> &g, vector<int> &color, int c) {
  color[s] = c;
  for (int to : g[s]) {
    if (color[to] == 0) dfs(to, g, color, c);
  }
}
int main() {
  ios_base::sync_with_stdio(0);
  int n, m;
  cin >> n >> m;
  vector<vector<char>> mat(n, vector<char>(m)), mat2 = mat;
  for (int i = 0; i < n; i++)
    for (int j = 0; j < m; j++) cin >> mat[i][j];
  vector<vector<int>> g(n + m);
  for (int i = 0; i < n; i++) {
    for (int j = 0; j < m; j++) {
      if (mat[i][j] == '#') {
        g[i].push_back(j + n);
        g[j + n].push_back(i);
      }
    }
  }
  vector<vector<int>> moves;
  vector<int> color(n + m);
  int c = 1;
  for (int i = 0; i < n + m; i++) {
    if (!color[i]) dfs(i, g, color, c++);
  }
  c--;
  for (int i = 0; i < n + m; i++) {
    color[i]--;
  }
  moves.resize(c);
  for (int i = 0; i < n + m; i++) {
    moves[color[i]].push_back(i);
  }
  for (int i = 0; i < n; i++)
    for (int j = 0; j < m; j++) mat2[i][j] = '.';
  for (int i = 0; i < c; i++) {
    vector<int> h, v;
    for (int j = 0; j < (int)moves[i].size(); j++) {
      if (moves[i][j] < n)
        h.push_back(moves[i][j]);
      else
        v.push_back(moves[i][j] - n);
    }
    for (int q = 0; q < h.size(); q++) {
      for (int w = 0; w < v.size(); w++) {
        mat2[h[q]][v[w]] = '#';
      }
    }
  }
  for (int i = 0; i < n; i++) {
    for (int j = 0; j < m; j++) {
      if (mat[i][j] != mat2[i][j]) {
        cout << "No";
        return 0;
      }
    }
  }
  cout << "Yes";
}
