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No
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 No

import java.io.OutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.util.Arrays;
import java.util.InputMismatchException;
import java.io.IOException;
import java.io.InputStream;

/**
 * Built using CHelper plug-in
 * Actual solution is at the top
 *
 * @author noob_coder
 */
public class Main {
        public static void main(String[] args) {
                InputStream inputStream = System.in;
                OutputStream outputStream = System.out;
                InputReader in = new InputReader(inputStream);
                PrintWriter out = new PrintWriter(outputStream);
                TaskB solver = new TaskB();
                solver.solve(1, in, out);
                out.close();
        }

        static class TaskB {
                public void solve(int testNumber, InputReader in, PrintWriter out) {
                        int n = in.i();
                        int m = in.i();
                        char[][] a = in.nm(n, m);
                        boolean[] vis = new boolean[n];

                        for (int i = 0; i < n; i++) {
                                vis[i] = true;
                                int count = 0;
                                for (int j = 0; j < m; j++) {
                                        if (a[i][j] == '#') count++;
                                }
                                for (int j = 0; j < n; j++) {
                                        if (j != i) {
                                                if (!vis[j]) {
                                                        boolean flag = false;
                                                        int count_j = 0;
                                                        for (int k = 0; k < m; k++) {
                                                                if (a[j][k] == '#') count_j++;
                                                                if (a[i][k] == '#' && a[j][k] == '#') {
                                                                        flag = true;
                                                                }
                                                        }
                                                        if (flag && count != count_j) {
                                                                out.println("No");
                                                                return;
                                                        } else if (count == count_j) {
                                                                vis[j] = true;
                                                        }
                                                }
                                        }
                                }
                        }
                        out.println("Yes");
                }

        }

        static class InputReader {
                InputStream is;
                private byte[] inbuf = new byte[1024];
                public int lenbuf = 0;
                public int ptrbuf = 0;

                public InputReader(InputStream is) {
                        this.is = is;
                }

                private int readByte() {
                        if (lenbuf == -1) throw new InputMismatchException();
                        if (ptrbuf >= lenbuf) {
                                ptrbuf = 0;
                                try {
                                        lenbuf = is.read(inbuf);
                                } catch (IOException e) {
                                        throw new InputMismatchException();
                                }
                                if (lenbuf <= 0) return -1;
                        }
                        return inbuf[ptrbuf++];
                }

                private boolean isSpaceChar(int c) {
                        return !(c >= 33 && c <= 126);
                }

                private int skip() {
                        int b;
                        while ((b = readByte()) != -1 && isSpaceChar(b)) ;
                        return b;
                }

                public char[] sa(int n) {
                        char[] buf = new char[n];
                        int b = skip(), p = 0;
                        while (p < n && !(isSpaceChar(b))) {
                                buf[p++] = (char) b;
                                b = readByte();
                        }
                        return n == p ? buf : Arrays.copyOf(buf, p);
                }

                public char[][] nm(int n, int m) {
                        char[][] map = new char[n][];
                        for (int i = 0; i < n; i++) map[i] = sa(m);
                        return map;
                }

                public int i() {
                        int num = 0, b;
                        boolean minus = false;
                        while ((b = readByte()) != -1 && !((b >= '0' && b <= '9') || b == '-')) ;
                        if (b == '-') {
                                minus = true;
                                b = readByte();
                        }

                        while (true) {
                                if (b >= '0' && b <= '9') {
                                        num = num * 10 + (b - '0');
                                } else {
                                        return minus ? -num : num;
                                }
                                b = readByte();
                        }
                }

        }
}

