package chelper;

import java.util.HashSet;
import java.util.Set;

import io.InputReader;
import io.OutputWriter;
import misc.SimpleSavingChelperSolution;


public class A extends SimpleSavingChelperSolution {

  public void solve(int testNumber, InputReader in, OutputWriter out) {
    wrapSolve(testNumber, in, out);
  }

  @Override
  public void solve(int testNumber) {
    int n = in.nextInt();
    int m = in.nextInt();

    boolean[][] a = new boolean[n][m];

    for (int i = 0; i < n; i++) {
      String s = in.nextString();
      for(int j = 0; j < m; j++) {
        a[i][j] = s.charAt(j) == '#';
      }
    }

    boolean ok = true;

    for (int i = 0; i < n; i++) {
      Set<Integer> atBaseLine = new HashSet<>();

      for (int j = 0; j < m; j++) {
        if (a[i][j]) {
          atBaseLine.add(j);
        }
      }

      for (int ii = i + 1; ii < n; ii++) {
        Set<Integer> atNextLine = new HashSet<>();

        for (int j = 0; j < m; j++) {
          if (a[ii][j]) {
            atNextLine.add(j);
          }
        }

        Set<Integer> intersection = new HashSet<>(atBaseLine);
        intersection.retainAll(atNextLine);

        if (!intersection.isEmpty() && !atBaseLine.equals(atNextLine)) {
          ok = false;
        }
      }
    }

    out.println(ok ? "Yes" : "No");
  }
}