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import java.io.BufferedReader;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.io.UnsupportedEncodingException;
import java.util.StringTokenizer;

public class Main {
    
    public static void main(String[] args) throws UnsupportedEncodingException, IOException {
        Reader.init(System.in);
        StringBuilder out = new StringBuilder();
        int r = Reader.nextInt(), c = Reader.nextInt();
        char[][] b = new char[r][], b2 = new char[c][r];
        for(int i = 0; i < r; i++)
            b[i] = Reader.nextLine().toCharArray();
        for(int i = 0; i < c; i++)
            for(int j = 0; j < r; j++)
                b2[i][j] = b[j][i];
        out.append(check(b) && check(b2) ? "Yes\n" : "No\n");
        PrintWriter pw = new PrintWriter(System.out);
        pw.print(out);
        pw.close();
    }
    
    static boolean check(char[][] c) {
        boolean[][] C = new boolean[c[0].length][c[0].length];
        boolean[] v = new boolean[c[0].length];
        for(int i = 0, j, k; i < c.length; i++)
            for(j = 0; j < c[i].length; j++)
                if(c[i][j] == '#') {
                    if(v[j]) {
                        for(k = 0; k < c[i].length; k++)
                            if((c[i][k] == '#' && !C[j][k]) || (c[i][k] == '.' && C[j][k]))
                                return false;
                    } else {
                        v[j] = true;
                        for(k = 0; k < c[i].length; k++)
                            if(c[i][k] == '#')
                                C[j][k] = true;
                    }
                }
        return true;
    }
}

class Reader {

    static BufferedReader reader;
    static StringTokenizer tokenizer;

    static void init(InputStream input) throws UnsupportedEncodingException {
        reader = new BufferedReader(
                new InputStreamReader(input, "UTF-8"));
        tokenizer = new StringTokenizer("");
    }
    
    static void init(String url) throws FileNotFoundException {
        reader = new BufferedReader(new FileReader(url));
        tokenizer = new StringTokenizer("");
    }

    static String next() throws IOException {
        while (!tokenizer.hasMoreTokens()) {
            //TODO add check for eof if necessary
            tokenizer = new StringTokenizer(
                    reader.readLine());
        }
        return tokenizer.nextToken();
    }

    static String nextLine() throws IOException {
        return reader.readLine();
    }

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

    static double nextDouble() throws IOException {
        return Double.parseDouble(next());
    }

    static long nextLong() throws IOException {
        return Long.parseLong(next());
    }
}