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//package com.company;

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

public class Main {
    static long TIME_START, TIME_END;
    public static void main(String[] args) throws IOException {
        Scanner sc = new Scanner(System.in);
//        Scanner sc = new Scanner(new FileInputStream("Test.in"));
        PrintWriter pw = new PrintWriter(System.out);
//        PrintWriter pw = new PrintWriter(new FileOutputStream("Test.out"));
//        PrintWriter pw = new PrintWriter(new FileOutputStream("Test.in"));

        Runtime runtime = Runtime.getRuntime();
        long usedMemoryBefore = runtime.totalMemory() - runtime.freeMemory();
        TIME_START = System.currentTimeMillis();
        Task t = new Task();
        t.solve(sc, pw);
        TIME_END = System.currentTimeMillis();
        long usedMemoryAfter = runtime.totalMemory() - runtime.freeMemory();
        pw.close();
//        System.out.println("Memory increased:" + (usedMemoryAfter-usedMemoryBefore) / 1000000 );
//        System.out.println("Time used: " + (TIME_END - TIME_START) + ".");


    }

    public static class Task {


        public void solve(Scanner sc, PrintWriter pw) throws IOException {
            int n = sc.nextInt();
            int m = sc.nextInt();
            int[][] grid = new int[n][m];
            int black = 0;
            for (int i = 0; i < n; i++) {
                String s = sc.next();
                for (int j = 0; j < m; j++) {
                    int c = s.charAt(j) == '.' ? 0 : 1;
                    if (c >= 1) {
                        black++;
                    }
                    grid[i][j] = c;
                }
            }
            int[] rowUse = new int[n];
            int[] colUse = new int[m];
            int iter = 0;
            while (black > 0) {
                iter++;
                if (iter >= 100) {
                    pw.println("No");
                    return;
                }
                for (int i = 0; i < n; i++) {
                    List<Integer> consider = new ArrayList<>();
                    for (int j = 0; j < m; j++) {
                        if (grid[i][j] == 1) {
                            if (colUse[j] == 1 || rowUse[i] == 1) {
                                pw.println("No");
                                return;
                            }
                            colUse[j] = 1;
//                            grid[i][j] = 0;
//                            black--;
                            consider.add(j);
                        }
                    }
                    if (consider.size() > 0) {
                        for (int j = 0; j < n; j++) {
                            if (grid[j][consider.get(0)] == 1) {
                                if (rowUse[j] == 1) {
                                    pw.println("No");
                                    return;
                                }
                                rowUse[j] = 1;
                                for (int c : consider) {
                                    if (grid[j][c] == 1) {
                                        grid[j][c] = 0;
                                        black--;
                                    } else {
                                        pw.println("No");
                                        return;
                                    }
                                }
                            }
                        }
                    }
                }
            }
            pw.println("Yes");
        }

    }

    static class Scanner {
        StringTokenizer st;
        BufferedReader br;

        public Scanner(InputStream s){  br = new BufferedReader(new InputStreamReader(s));}

        public Scanner(FileReader s) throws FileNotFoundException {br = new BufferedReader(s);}

        public String next() throws IOException
        {
            while (st == null || !st.hasMoreTokens())
                st = new StringTokenizer(br.readLine());
            return st.nextToken();
        }

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

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

        public String nextLine() throws IOException {return br.readLine();}

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

        public boolean ready() throws IOException {return br.ready();}
    }
}
