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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 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){
                        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;
                        }

                    }




                }


            }
        }


//        for(int l=0;l<N;l++){
//            for(int j=0;j<M;j++)
//                System.out.print(ans[l][j]+" ");
//
//            System.out.println();
//        }


        System.out.println("Yes");



    }
}