9 5
.....
#....
..#..
.....
.#..#
...#.
.#...
....#
.....
 4 10
..#......#
.....##...
#.........
.#.......#
 50 2
..
..
#.
..
.#
..
..
..
.#
..
..
.#
##
..
..
..
.#
..
..
.#
..
..
.#
..
..
.#
..
.#
..
.#
..
.#
.#
.#
..
..
..
.#
.#
.#
..
..
.#
.#
..
..
..
..
..
..
 2 50
...#.##.###...#.#..##....##..........#.#..#.#####.
...#.##.###...#.#..##....##..........#.#..#.#####.
 1 1
#
 3 3
.##
#.#
##.
 50 8
.....#..
........
........
.....#..
.....#..
........
........
........
........
...#....
...#....
........
...#....
#.#.#...
...#....
...#....
........
...#....
...#....
...#....
........
#.#.#...
.....#..
........
#.#.#...
#.#.#...
#.#.#...
...#....
........
........
........
#.#.#...
........
.....#..
........
........
........
........
........
........
.....#..
........
........
........
.....#..
#.#.#...
...#....
........
........
........
 1 1
.
 25 16
.............#..
.............#..
.......#...#....
............#...
.....#..........
.....#..........
#...............
................
........#.......
................
................
.#..............
#...............
.....#..........
.#..............
............#...
................
................
................
........#.......
..#.............
..........#.....
.......#...#....
.............#..
..........#.....
 25 16
..............#.
................
...#...#........
........#.#.....
..............##
..............#.
.......#........
......#.........
............#...
.........#.....#
..............#.
.......#........
#...........#...
...#.#..........
.#..............
................
......#.....#...
.......#........
........#.....#.
................
......#.........
..#.............
................
...#.#..........
.#..............
 10 15
.......#.......
.....#.........
....#..........
....#..........
.....#.........
.....#.........
#.............#
...#..#........
...............
.............#.
 4 10
###..#..##
...##..#..
.##..#..#.
.........#
 2 5
.####
#..##
 5 2
##
##
..
##
..
 2 2
##
#.
 50 1
.
.
#
.
#
.
#
.
.
#
#
#
.
#
#
#
#
.
.
.
.
.
.
.
.
.
#
#
#
#
.
.
.
.
.
#
.
.
.
#
#
.
.
#
#
.
.
#
#
.
 5 2
#.
##
##
#.
..
 2 3
#.#
###
 2 1
.
#
 2 3
#.#
##.
 10 10
..........
..........
..........
..........
.#.......#
#.........
......#...
..........
..........
#.....#...
 4 4
###.
##.#
#.##
.###

No
 No
 No
 Yes
 Yes
 No
 Yes
 Yes
 Yes
 No
 Yes
 No
 No
 Yes
 No
 Yes
 No
 No
 Yes
 No
 No
 No

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

public class B {

    MyScanner in;
    PrintWriter out;

    public static void main(String[] args) throws Exception {
        new B().run();
    }

    public void run() throws Exception {
        in = new MyScanner();
        out = new PrintWriter(System.out);

        solve();

        out.close();
    }

    int n, m;

    boolean isClear(char[][] a) {
        for (int i = 0; i < n; i++) {
            for (int j = 0; j < m; j++) {
                if (a[i][j] != '.') {
                    return false;
                }
            }
        }
        return true;
    }

    int findRow(char[][] a) {
        for (int i = 0; i < n; i++) {
            for (int j = 0; j < m; j++) {
                if (a[i][j] == '#') {
                    return i;
                }
            }
        }

        return -1;
    }

    HashSet<Integer> getCols(char[][] a, int row) {
        HashSet<Integer> ans = new HashSet<>();

        for (int j = 0; j < m; j++) {
            if (a[row][j] == '#') {
                ans.add(j);
            }
        }

        return ans;
    }

    HashSet<Integer> getRows(char[][] a, int col) {
        HashSet<Integer> ans = new HashSet<>();

        for (int i = 0; i < n; i++) {
            if (a[i][col] == '#') {
                ans.add(i);
            }
        }

        return ans;
    }

    boolean orthogonal(char[][] a, ArrayList<HashSet<Integer>> rowSets) {
        HashSet<Integer> firstRowSet = rowSets.get(0);

        for (int i = 1; i < rowSets.size(); i++) {
            if (!rowSets.get(i).containsAll(firstRowSet) || !firstRowSet.containsAll(rowSets.get(i))) {
                return false;
            }
        }

        return true;
    }

    void removeFromField(char[][] a, HashSet<Integer> cols, ArrayList<HashSet<Integer>> rowSets) {
        HashSet<Integer> firstRowSet = rowSets.get(0);

        for (int i : firstRowSet) {
            for (int j : cols) {
                a[i][j] = '.';
            }
        }
    }

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

        char[][] a = new char[n][];
        for (int i = 0; i < n; i++) {
            a[i] = in.next().toCharArray();
        }

        HashSet<Integer> forbiddenRows = new HashSet<>();
        HashSet<Integer> forbiddenCols = new HashSet<>();

        while (!isClear(a)) {
            int initRow = findRow(a);
            HashSet<Integer> cols = getCols(a, initRow);
            ArrayList<HashSet<Integer>> rowSets = new ArrayList<>();

            for (int col : cols) {
                rowSets.add(getRows(a, col));
            }

            if (!orthogonal(a, rowSets)) {
                out.println("No");
                return;
            }

            for (int col : cols) {
                if (forbiddenCols.contains(col)) {
                    out.println("No");
                    return;
                }
            }

            for (int row : rowSets.get(0)) {
                if (forbiddenRows.contains(row)) {
                    out.println("No");
                    return;
                }
            }

            removeFromField(a, cols, rowSets);

            forbiddenCols.addAll(cols);
            forbiddenRows.addAll(rowSets.get(0));
        }

        out.println("Yes");
    }

    class MyScanner {

        BufferedReader br;
        StringTokenizer st;

        public MyScanner() throws Exception {
            br = new BufferedReader(new InputStreamReader(System.in));
        }

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

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

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

        boolean nextBoolean() throws Exception {
            return Boolean.parseBoolean(next());
        }

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