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

public class B {
    String fileName = "<name>";

    public boolean check(int row, Set<Integer> rowsRef) {
        for (int curRow : rowsRef) {
            if (!rows.get(curRow).equals(rows.get(row)))
                return false;
        }
        return true;
    }

    public List<Set<Integer>> rows;
    public List<Set<Integer>> cols;

    public void solve() throws IOException {
        int n = nextInt();
        int m = nextInt();
        boolean[][] map = new boolean[n][m];
        rows = new ArrayList<>(n);
        cols = new ArrayList<>(m);
        for (int i = 0; i < n; i++) {
            rows.add(new TreeSet<>());
        }
        for (int i = 0; i < m; i++) {
            cols.add(new TreeSet<>());
        }
        for (int i = 0; i < n; i++) {
            String tmp = nextToken();
            for (int j = 0; j < tmp.length(); j++) {
                map[i][j] = tmp.charAt(j) == '#';
                if (map[i][j]) {
                    rows.get(i).add(j);
                    cols.get(j).add(i);
                }
            }
        }
        int row = 0;
        for (Set<Integer> ref : rows) {
            for (int col : ref) {
                Set<Integer> rowsRef = cols.get(col);
                if (rowsRef.size() > 1 && !check(row,rowsRef)){
                    out.print("No");
                    return;
                }
            }
            row++;
        }
        out.print("Yes");
    }

    public void run() {
        try {
            br = new BufferedReader(new InputStreamReader(System.in));
            out = new PrintWriter(System.out);

            solve();

            out.close();
        } catch (IOException e) {
            e.printStackTrace();
            System.exit(1);
        }
    }

    BufferedReader br;
    StringTokenizer in;
    PrintWriter out;

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

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

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

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

    public static void main(String[] args) throws IOException {
        Locale.setDefault(Locale.US);
        new B().run();
    }
}