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

public class TaskA {
    FastScanner in;
    PrintWriter out;

    public void solve() throws IOException {
        int n = in.nextInt();
        int m = in.nextInt();

        char[][] table = new char[n][];
        char[][] real_table = new char[n][m];

        boolean[] visited = new boolean[n];

        for (int i = 0; i < n; i++) {
            String str = in.next();
//            System.out.println(str);
            table[i] = str.toCharArray();
        }

        for (int i = 0; i < n; i++) {
            if(visited[i]) continue;

            for (int j = 0; j < m; j++) {
                if(table[i][j] == '#'){
                    for (int k = 0; k < n; k++) {
//                        if(visited[k] = true) continue;
                        if(table[k][j] == '#'){
                            visited[k] = true;

                            System.arraycopy(table[i], 0, real_table[k], 0, m);

                        }
                    }
                }
            }

        }

        boolean isOK = true;

        for (int i = 0; i < n; i++) {
            for (int j = 0; j < m; j++) {
                if(table[i][j] != real_table[i][j]) isOK = false;
            }
        }

        if(isOK){
            System.out.println("Yes");
        }else{
            System.out.println("No");
        }


    }

    public void run() {
        try {
            in = new FastScanner(System.in);
            out = new PrintWriter(System.out);

            solve();

            out.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    class FastScanner {
        BufferedReader br;
        StringTokenizer st;

        FastScanner(InputStream is) {
            br = new BufferedReader(new InputStreamReader(is));
        }

        FastScanner(File f) throws FileNotFoundException {
            this(new FileInputStream(f));
        }

        String next() {
            while (st == null || !st.hasMoreTokens()) {
                try {
                    st = new StringTokenizer(br.readLine());
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            return st.nextToken();
        }

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

    public static void main(String[] arg) {
        new TaskA().run();
    }
}