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import java.io.*;
import java.util.Arrays;
import java.util.HashSet;
import java.util.Set;

public class BMosaic {

  private static final String REGEX = " ";
  private static final Boolean DEBUG = false;
  private static final String FILE_NAME = "input.txt";


  public static void main(String[] args) throws IOException {
    if (DEBUG) {
      generate();
    }
    Solver solver = new Solver();
    solver.readData();
    solver.solve();
    solver.print();
  }

  private static void generate() throws IOException {
//    FileWriter writer = new FileWriter("input.txt");
//    writer.close();
  }

  private static class Solver {
    private StringBuilder myStringBuilder = new StringBuilder();
    int n, m;
    char[][] mos;

    void readData() throws IOException {
      Scanner scanner = new Scanner();
      n = scanner.nextInt();
      m = scanner.nextInt();
      mos = new char[n][m];
      for (int i = 0; i < n; i++) {
        String s = scanner.nextLine();
        for (int j = 0; j < m; j++) {
          mos[i][j] = s.charAt(j);
        }
      }
      scanner.close();
    }

    void solve() {

      for (int i = 0; i < n; i++) {
        int col = -1;
        for (int j = 0; j < m; j++) {
          if (mos[i][j] == '#') {
            col = j;
            break;
          }
        }
        if (col == -1) {
          continue;
        }
        Set<Integer> rowsToCheck = new HashSet<>();
        for (int i1 = 0; i1 < n; i1++) {
          if (i1 == i) {
            continue;

          }
          if (mos[i1][col] == '#') {
            rowsToCheck.add(i1);
          }
        }
        for (Integer rowToCheck : rowsToCheck) {
          if (!Arrays.equals(mos[i], mos[rowToCheck])) {
            out("No");
            return;
          }
        }
      }
      out("Yes");

    }

    void print() {
      System.out.println(myStringBuilder);
    }


    void out(Object object) {
      myStringBuilder.append(object);
    }

    void out(String string) {
      myStringBuilder.append(string);
    }

    public void out(boolean b) {
      myStringBuilder.append(b);
    }

    public void out(char c) {
      myStringBuilder.append(c);
    }

    public void out(int i) {
      myStringBuilder.append(i);
    }

    public void out(long lng) {
      myStringBuilder.append(lng);
    }

    public void out(float f) {
      myStringBuilder.append(f);
    }

    public void out(double d) {
      myStringBuilder.append(d);
    }

    public void newLine() {
      myStringBuilder.append("\n");
    }

    @SuppressWarnings("SameParameterValue")
    int[] splitInteger(String string, int n) {
      final String[] split = string.split(REGEX, n);
      int[] result = new int[split.length];
      for (int i = 0; i < n; ++i) {
        result[i] = Integer.parseInt(split[i]);
      }
      return result;
    }

    public int[] splitInteger(String string) {
      return splitInteger(string, 0);
    }


    @SuppressWarnings("SameParameterValue")
    long[] splitLong(String string, int n) {
      final String[] split = string.split(REGEX, n);
      long[] result = new long[split.length];
      for (int i = 0; i < n; ++i) {
        result[i] = Long.parseLong(split[i]);
      }
      return result;
    }

    public long[] splitLong(String string) {
      return splitLong(string, 0);
    }

    @SuppressWarnings("SameParameterValue")
    double[] splitDouble(String string, int n) {
      final String[] split = string.split(REGEX, n);
      double[] result = new double[split.length];
      for (int i = 0; i < n; ++i) {
        result[i] = Double.parseDouble(split[i]);
      }
      return result;
    }

    public double[] splitDouble(String string) {
      return splitDouble(string, 0);
    }

    @SuppressWarnings("SameParameterValue")
    String[] splitString(String string, int n) {
      return string.split(REGEX, n);
    }

    public int max(int a, int b) {
      return Math.max(a, b);
    }

    public int max(int[] arr) {
      int max = Integer.MIN_VALUE;
      for (int x : arr) {
        max = max(max, x);
      }
      return max;
    }

    public long max(long a, long b) {
      return Math.max(a, b);
    }

    public int min(int a, int b) {
      return Math.min(a, b);
    }

    public long min(long a, long b) {
      return Math.min(a, b);
    }

    public double max(double a, double b) {
      return Math.max(a, b);
    }

    public double min(double a, double b) {
      return Math.min(a, b);
    }

    private final static int MOD = 1000000009;

    int multMod(int a, int b) {
      return ((a % MOD) * (b % MOD)) % MOD;
    }

    int sumMod(int a, int b) {
      return ((a % MOD) + (b % MOD)) % MOD;
    }

    long multMod(long a, long b) {
      return ((a % MOD) * (b % MOD)) % MOD;
    }

    long sumMod(long a, long b) {
      return ((a % MOD) + (b % MOD)) % MOD;
    }

    int sum(int[] arr) {
      int sum = 0;
      for (int i = 0; i < arr.length; i++) {
        sum += arr[i];
      }
      return sum;
    }

    long sum(long[] arr) {
      long sum = 0;
      for (int i = 0; i < arr.length; i++) {
        sum += arr[i];
      }
      return sum;
    }

    private class Scanner {
      private int currentIndex = 0;
      private String[] objects;
      private final BufferedReader myReader;
      private Computable<Character> charComputer;
      private Computable<Double> doubleComputer;
      private Computable<Integer> intComputer;
      private Computable<Long> longComputer;

      Scanner() throws FileNotFoundException {
        InputStream in = DEBUG ? new FileInputStream(FILE_NAME) : System.in;
        myReader = new BufferedReader(new InputStreamReader(in));
        charComputer = () -> objects[currentIndex].charAt(0);
        doubleComputer = () -> Double.parseDouble(objects[currentIndex]);
        intComputer = () -> Integer.parseInt(objects[currentIndex]);
        longComputer = () -> Long.parseLong(objects[currentIndex]);
      }

      String nextLine() throws IOException {
        objects = null;
        currentIndex = 0;
        return myReader.readLine();
      }

      int nextInt() throws IOException {
        return next(intComputer);
      }

      int[] nextIntArray(int n) throws IOException {
        return splitInteger(nextLine(), n);
      }

      long[] nextLongArray(int n) throws IOException {
        return splitLong(nextLine(), n);
      }

      long nextLong() throws IOException {
        return next(longComputer);

      }

      double nextDouble() throws IOException {
        return next(doubleComputer);

      }

      char nextChar() throws IOException {
        return next(charComputer);
      }

      <T> T next(Computable<T> computer) throws IOException {
        T result;
        if (objects == null || currentIndex >= objects.length) {
          String s = myReader.readLine();
          objects = s.split(" ");
          currentIndex = 0;
        }
        result = computer.compute();
        currentIndex++;
        return result;
      }

      public void close() throws IOException {
        myReader.close();
      }

    }

    interface Computable<T> {
      T compute();
    }

  }

}
