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//package CFMAR24;

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

public class Q2 {

    static class InputReader {
        public BufferedReader reader;
        public StringTokenizer tokenizer;

        public InputReader() {
            reader = new BufferedReader(new InputStreamReader(System.in), 32768);
            tokenizer = null;
        }

        public InputReader(InputStream stream) {
            reader = new BufferedReader(new InputStreamReader(System.in), 32768);
            tokenizer = null;
        }

        public String next() {
            while (tokenizer == null || !tokenizer.hasMoreTokens()) {
                try {
                    tokenizer = new StringTokenizer(reader.readLine());
                } catch (IOException e) {
                    throw new RuntimeException(e);
                }
            }
            return tokenizer.nextToken();
        }

        public char nextChar() {
            return next().charAt(0);
        }

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

        public long nextLong() {
            return Long.parseLong(next());
        }

        public double nextDouble() {
            return Double.parseDouble(next());
        }
    }


    public static void main(String[] args) {

        InputReader in = new InputReader();
        int N = in.nextInt();
        int M = in.nextInt();

        String input1[] = new String[N];

        for (int i = 0; i < N; i++) {
            input1[i] = in.next();
        }


        char input[][] = new char[N][M];

        for (int l = 0; l < N; l++) {
            for (int j = 0; j < M; j++)
                input[l][j] = input1[l].charAt(j);
        }

        // int ans1[]=new int[N];


        if (N == 1) {
            System.out.println("Yes");
        }

        int flag = 0;
        int ans[][] = new int[N][M];

        for (int i = 0; i < N; i++) {
            flag = 0;

            for (int j = 0; j < M; j++) {

                if (input[i][j] == '#') {

                    if (ans[i][j] != 0 && flag == 0) {
                        //    ans1[ans[i][j]]++
                        continue;
                    } else {
                        flag = 1;
                    }


                    for (int k = i; k < N; k++) {

                        if (input[k][j] == '#') {

                            if (ans[k][j] != 0) {
                                System.out.println("No");
                                return;
                            }
                            ans[k][j] = i + 1;
                            //      ans1[i]++;
                        }

                    }


                }


            }
        }

        int sol[] = new int[N];
        if (N != 1) {

            for (int l = 0; l < N; l++) {
                int count = 0;
                int val = 0;
                for (int j = 0; j < M; j++) {
                    if (ans[l][j] != 0) {
                        val = ans[l][j];
                        count++;
                    }

                }
                if (val < N) {

                    if (sol[val] == 0) {
                        sol[val] = count;
                        continue;
                    }

                    if (sol[val] != count) {
                        System.out.println("No");
                        return;
                    }
                }
                //  System.out.println();
            }


            System.out.println("Yes");


        }
    }
}