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import java.util.*;
import java.io.*;

public class A {
  FastScanner in;
  PrintWriter out;

  char[][] table;
  boolean[][] checked;
  Set<Integer> rows = new HashSet<>();
  Set<Integer> cols = new HashSet<>();
  
  public void check(int x, int y) {
    checked[x][y] = true;
    rows.add(x);
    cols.add(y);
    for (int i = 0; i < table.length; i++) {
      if (i != x && table[i][y] == '#' && !checked[i][y]) {
        check(i, y);
      }
    }
    for (int j = 0; j < table[0].length; j++) {
      if (j != y && table[x][j] == '#' && !checked[x][j]) {
        check(x, j);
      }
    }
  }

  public void solve() throws IOException {
    int n = in.nextInt();
    int m = in.nextInt();
    table = new char[n][];
    checked = new boolean[n][m];
    for (int i = 0; i < n; i++) {
      table[i] = in.next().toCharArray();
    }
    for (int i = 0; i < n; i++) {
      for (int j = 0; j < m; j++) {
        if (table[i][j] == '#' && !checked[i][j]) {
          rows.clear();
          cols.clear();
          check(i, j);
          for (int rowi: rows) {
            for (int coli: cols) {
              if (table[rowi][coli] != '#') {
                out.println("No");
                return;
              }
            }
          }
        }
      }
    }
    out.println("Yes");
  }

  public void run() {
    try {
      in = new FastScanner(System.in);
      out = new PrintWriter(System.out);
      solve();

      out.close();
    } catch (IOException e) {
      e.printStackTrace();
    }
  }

  class FastScanner {
    BufferedReader br;
    StringTokenizer st;

    FastScanner(InputStream is) {
      br = new BufferedReader(new InputStreamReader(is));
    }

    String next() {
      while (st == null || !st.hasMoreTokens()) {
        try {
          st = new StringTokenizer(br.readLine());
        } catch (IOException e) {
          e.printStackTrace();
        }
      }
      return st.nextToken();
    }

    int nextInt() {
      return Integer.parseInt(next());
    }
  }

  public static void main(String[] arg) {
    new A().run();
  }
}