#include <bits/stdc++.h>
using namespace std;
string second[100];
int x[100], y[100];
vector<int> a, b;
bool u[100][100];
bool uu[100][100];
bool ux[100], uy[100];
int n, m;
void dfs(int x, int y) {
  ux[x] = uy[y] = true;
  u[x][y] = true;
  for (int i = 0; i < n; i++)
    if (second[i][y] == '#' && !u[i][y]) dfs(i, y);
  for (int j = 0; j < m; j++)
    if (second[x][j] == '#' && !u[x][j]) dfs(x, j);
}
int main() {
  cin >> n >> m;
  for (int i = 0; i < n; i++) cin >> second[i];
  for (int i = 0; i < n; i++)
    for (int j = 0; j < m; j++)
      if (second[i][j] == '#' && !u[i][j]) {
        for (int i = 0; i < n; i++) ux[i] = false;
        for (int i = 0; i < m; i++) uy[i] = false;
        dfs(i, j);
        a.clear();
        b.clear();
        for (int i = 0; i < n; i++)
          if (ux[i]) a.push_back(i);
        for (int j = 0; j < m; j++)
          if (uy[j]) b.push_back(j);
        for (int i = 0; i < n; i++)
          for (int j = 0; j < m; j++) uu[i][j] = false;
        for (int i = 0; i < a.size(); i++)
          for (int j = 0; j < b.size(); j++) {
            uu[a[i]][b[j]] = true;
          }
        for (int i = 0; i < n; i++)
          for (int j = 0; j < m; j++) {
            if (ux[i] && second[i][j] == '#' && !uu[i][j]) {
              cout << "No";
              return 0;
            }
            if (second[i][j] == '.' && uu[i][j]) {
              cout << "No";
              return 0;
            }
          }
      }
  cout << "Yes";
  return 0;
}
