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import java.io.OutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.io.ByteArrayOutputStream;
import java.util.Set;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.FileNotFoundException;
import java.io.File;
import java.util.HashSet;
import java.util.StringTokenizer;
import java.io.Writer;
import java.io.BufferedReader;
import java.io.FileReader;
import java.io.InputStream;

/**
 * Built using CHelper plug-in
 * Actual solution is at the top
 */
public class Main {
  public static void main(String[] args) {
    InputStream inputStream = System.in;
    OutputStream outputStream = System.out;
    InputReader in = new InputReader(inputStream);
    OutputWriter out = new OutputWriter(outputStream);
    TaskA solver = new TaskA();
    solver.solve(1, in, out);
    out.close();
  }

  static class TaskA extends SimpleSavingChelperSolution {
    public void solve(int testNumber, InputReader in, OutputWriter out) {
      wrapSolve(testNumber, in, out);
    }


    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");
    }

  }

  static class InputReader {
    private BufferedReader br;
    private StringTokenizer in;

    public InputReader(String fileName) {
      try {
        br = new BufferedReader(new FileReader(fileName));
      } catch (IOException e) {
        throw new RuntimeException(e);
      }
    }

    public InputReader(InputStream inputStream) {
      br = new BufferedReader(new InputStreamReader(inputStream));
    }

    private boolean hasMoreTokens() {
      while (in == null || !in.hasMoreTokens()) {
        String s = nextLine();
        if (s == null) {
          return false;
        }
        in = new StringTokenizer(s);
      }
      return true;
    }

    public String nextString() {
      return hasMoreTokens() ? in.nextToken() : null;
    }

    public String nextLine() {
      try {
        in = null;
        return br.readLine();
      } catch (Exception e) {
        e.printStackTrace();
        return null;
      }
    }

    public int nextInt() {
      return Integer.parseInt(nextString());
    }

  }

  static abstract class SimpleSavingChelperSolution extends SavingChelperSolution {

    public String processOutputPreCheck(int testNumber, String output) {
      return output;
    }


    public String processOutputPostCheck(int testNumber, String output) {
      return output;
    }

  }

  static abstract class SavingChelperSolution {
    protected int testNumber;
    public InputReader in;
    public OutputWriter out;
    private OutputWriter toFile;
    private boolean local = new File("chelper.properties").exists();
    public OutputWriter debug;

    {
      if (local) {
        debug = new OutputWriter(System.err);
      } else {
        debug = new OutputWriter(new OutputStream() {

          public void write(int b) {
          }
        });
      }
    }

    public SavingChelperSolution() {
      try {
        toFile = new OutputWriter("last_test_output.txt");
      } catch (FileNotFoundException e) {
        throw new RuntimeException(e);
      }
    }

    public abstract void solve(int testNumber);

    public abstract String processOutputPreCheck(int testNumber, String output);

    public abstract String processOutputPostCheck(int testNumber, String output);

    public void wrapSolve(int testNumber, InputReader in, OutputWriter out) {
      this.testNumber = testNumber;

      ByteArrayOutputStream substituteOutContents = new ByteArrayOutputStream();
      OutputWriter substituteOut = new OutputWriter(substituteOutContents);

      this.in = in;
      this.out = substituteOut;

      solve(testNumber);
      substituteOut.flush();

      String result = substituteOutContents.toString();

      result = processOutputPreCheck(testNumber, result);
      out.print(result);
      out.flush();

      if (local) {
        debug.flush();

        result = processOutputPostCheck(testNumber, result);
        toFile.print(result);
        toFile.flush();
      }
    }

  }

  static class OutputWriter extends PrintWriter {

    public void close() {
      super.close();
    }

    public OutputWriter(String fileName) throws FileNotFoundException {
      super(fileName);
    }

    public OutputWriter(OutputStream outputStream) {
      super(outputStream);
    }

    public OutputWriter(Writer writer) {
      super(writer);
    }

  }
}

