#include <bits/stdc++.h>
using namespace std;
int static fast = []() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  return 0;
}();
int main() {
  int r, c;
  cin >> r >> c;
  vector<int> used_rows(r, 0);
  vector<int> used_cols(c, 0);
  vector<string> grid;
  string s;
  for (int i = 0; i < r; i++) {
    cin >> s;
    grid.push_back(s);
  }
  for (int i = 0; i < r; i++) {
    for (int j = 0; j < c; j++) {
      if (grid[i][j] == '#') {
        if (used_rows[i] == 1 || used_cols[j] == 1) {
          cout << "No"
               << "\n";
          return 0;
        }
        vector<int> rs;
        vector<int> cs;
        for (int c2 = 0; c2 < c; c2++) {
          if (grid[i][c2] == '#') {
            if (used_cols[c2] == 1) {
              cout << "No"
                   << "\n";
              return 0;
            }
            used_cols[c2] = 1;
            cs.push_back(c2);
          }
        }
        for (int r2 = 0; r2 < r; r2++) {
          if (grid[r2][j] == '#') {
            if (used_rows[r2] == 1) {
              cout << "No"
                   << "\n";
              return 0;
            }
            used_rows[r2] = 1;
            rs.push_back(r2);
          }
        }
        for (int r2 : rs) {
          for (int c2 : cs) {
            if (grid[r2][c2] != '#') {
              cout << "No"
                   << "\n";
              return 0;
            } else {
              grid[r2][c2] = '.';
            }
          }
        }
      }
    }
  }
  cout << "Yes"
       << "\n";
  return 0;
}
