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import java.io.OutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.io.BufferedWriter;
import java.util.Set;
import java.util.InputMismatchException;
import java.io.IOException;
import java.util.HashSet;
import java.io.Writer;
import java.io.OutputStreamWriter;
import java.io.InputStream;

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

    static class TaskB {
        public void solve(int testNumber, InputReader in, OutputWriter out) {
            int n = in.nextInt(), m = in.nextInt();
            String grid[] = new String[n];
            for (int i = 0; i < n; i++) {
                grid[i] = in.next();
            }
            boolean visited[][] = new boolean[n][m];
            for (int i = 0; i < n; i++) {
                for (int j = 0; j < m; j++) {
                    if (grid[i].charAt(j) == '#' && !visited[i][j]) {
                        Set<Integer> rows = new HashSet<>();
                        Set<Integer> columns = new HashSet<>();
                        isPos(i, j, grid, rows, columns, visited);
                        if (!isValid(grid, rows, columns)) {
                            out.println("No");
                            return;
                        }
                    }
                }
            }
            out.println("Yes");

        }

        private boolean isValid(String grid[], Set<Integer> row, Set<Integer> colums) {
            for (int r : row) {
                for (int c : colums) {
                    if (grid[r].charAt(c) != '#') {
                        return false;
                    }
                }
            }
            return true;
        }

        public void isPos(int r, int c, String grid[], Set<Integer> rows, Set<Integer> columns, boolean visited[][]) {
            if (visited[r][c]) return;
            rows.add(r);
            columns.add(c);
            visited[r][c] = true;
            for (int i = 0; i < grid[r].length(); i++) {
                if (grid[r].charAt(i) == '#') {
                    isPos(r, i, grid, rows, columns, visited);
                }
            }
            for (int i = 0; i < grid.length; i++) {
                if (grid[i].charAt(c) == '#') {
                    isPos(i, c, grid, rows, columns, visited);
                }
            }
        }

    }

    static class InputReader {
        private InputStream stream;
        private byte[] buf = new byte[1024];
        private int curChar;
        private int numChars;
        private InputReader.SpaceCharFilter filter;

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

        public int read() {
            if (numChars == -1) {
                throw new InputMismatchException();
            }
            if (curChar >= numChars) {
                curChar = 0;
                try {
                    numChars = stream.read(buf);
                } catch (IOException e) {
                    throw new InputMismatchException();
                }
                if (numChars <= 0) {
                    return -1;
                }
            }
            return buf[curChar++];
        }

        public int readInt() {
            int c = read();
            while (isSpaceChar(c)) {
                c = read();
            }
            int sgn = 1;
            if (c == '-') {
                sgn = -1;
                c = read();
            }
            int res = 0;
            do {
                if (c < '0' || c > '9') {
                    throw new InputMismatchException();
                }
                res *= 10;
                res += c - '0';
                c = read();
            } while (!isSpaceChar(c));
            return res * sgn;
        }

        public String readString() {
            int c = read();
            while (isSpaceChar(c)) {
                c = read();
            }
            StringBuilder res = new StringBuilder();
            do {
                if (Character.isValidCodePoint(c)) {
                    res.appendCodePoint(c);
                }
                c = read();
            } while (!isSpaceChar(c));
            return res.toString();
        }

        public boolean isSpaceChar(int c) {
            if (filter != null) {
                return filter.isSpaceChar(c);
            }
            return isWhitespace(c);
        }

        public static boolean isWhitespace(int c) {
            return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1;
        }

        public String next() {
            return readString();
        }

        public int nextInt() {
            return readInt();
        }

        public interface SpaceCharFilter {
            public boolean isSpaceChar(int ch);

        }

    }

    static class OutputWriter {
        private final PrintWriter writer;

        public OutputWriter(OutputStream outputStream) {
            writer = new PrintWriter(new BufferedWriter(new OutputStreamWriter(outputStream)));
        }

        public OutputWriter(Writer writer) {
            this.writer = new PrintWriter(writer);
        }

        public void print(Object... objects) {
            for (int i = 0; i < objects.length; i++) {
                if (i != 0) {
                    writer.print(' ');
                }
                writer.print(objects[i]);
            }
        }

        public void println(Object... objects) {
            print(objects);
            writer.println();
        }

        public void close() {
            writer.close();
        }

    }
}

