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import java.io.OutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.io.OutputStream;
import java.util.Set;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.FileNotFoundException;
import java.util.HashSet;
import java.util.List;
import java.util.stream.Stream;
import java.util.StringTokenizer;
import java.io.Writer;
import java.io.BufferedReader;
import java.util.LinkedList;
import java.io.InputStream;

/**
 * Built using CHelper plug-in
 * Actual solution is at the top
 *
 * @author Asgar Javadov
 */
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();
            int m = in.nextInt();
            char[][] cell = in.readCharMatrix(n, m);

            Graph graph = new Graph(n + m);

            for (int i = 0; i < cell.length; ++i) {
                for (int j = 0; j < cell[0].length; j++) {
                    if (cell[i][j] == '#')
                        graph.addEdge(i, n + j);
                }
            }

            Set<Integer> rowSet = new HashSet<>();
            Set<Integer> columnSet = new HashSet<>();

            boolean[] rows = new boolean[n];
            boolean[] columns = new boolean[m];

            boolean res = true;
            for (int i = 0; i < n; ++i) {
                if (!rows[i]) {
                    rowSet.add(i);
                    dfs(i, graph, rows, columns, rowSet, columnSet, true);
                    res &= assertTrue(rowSet, columnSet, cell);
                    if (!res) {
                        out.println("No");
                        return;
                    }
                    rowSet.clear();
                    columnSet.clear();
                }
            }

            if (res) {
                out.println("Yes");
            }
        }

        private boolean assertTrue(Set<Integer> rowSet, Set<Integer> columnSet, char[][] cell) {
            for (int row : rowSet) {
                for (int col : columnSet) {
                    if (cell[row][col - cell.length] != '#')
                        return false;
                }
            }
            return true;
        }

        private void dfs(int v, Graph graph, boolean[] rows, boolean[] columns, Set<Integer> rowsSet, Set<Integer> colsSet, boolean isRow) {
            if (isRow) {
                rows[v] = true;
                for (int column : graph.getEdgesFrom(v)) {
                    if (!columns[column - rows.length]) {
                        colsSet.add(column);
                        dfs(column, graph, rows, columns, rowsSet, colsSet, false);
                    }
                }
            } else {
                columns[v - rows.length] = true;
                for (int row : graph.getEdgesFrom(v)) {
                    if (!rows[row]) {
                        rowsSet.add(row);
                        dfs(row, graph, rows, columns, rowsSet, colsSet, true);
                    }
                }
            }
        }

    }

    static class OutputWriter extends PrintWriter {
        public OutputWriter(OutputStream outputStream) {
            super(outputStream);
        }

        public OutputWriter(Writer writer) {
            super(writer);
        }

        public OutputWriter(String filename) throws FileNotFoundException {
            super(filename);
        }

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

    }

    static class InputReader extends BufferedReader {
        StringTokenizer tokenizer;

        public InputReader(InputStream inputStream) {
            super(new InputStreamReader(inputStream), 32768);
        }

        public InputReader(String filename) {
            super(new InputStreamReader(Thread.currentThread().getContextClassLoader().getResourceAsStream(filename)));
        }

        public String next() {
            while (tokenizer == null || !tokenizer.hasMoreTokens()) {
                try {
                    tokenizer = new StringTokenizer(readLine());
                } catch (IOException e) {
                    throw new RuntimeException();
                }
            }
            return tokenizer.nextToken();
        }

        public Integer nextInt() {
            return Integer.valueOf(next());
        }

        public char[][] readCharMatrix(int n, int m) {
            char[][] result = new char[n][];
            for (int i = 0; i < n; i++) {
                result[i] = next().toCharArray();
            }
            return result;
        }

    }

    static class Graph {
        protected int V;
        protected boolean directed = false;
        private List<Integer>[] edges;

        public Graph(int v) {
            this(v, false);
        }

        @SuppressWarnings("unchecked")
        public Graph(int v, boolean directed) {
            this.V = v;
            this.directed = directed;
            this.edges = Stream.generate(LinkedList<Integer>::new).limit(V).toArray(List[]::new);
        }

        public void addEdge(int u, int v) {
            edges[u].add(v);
            if (!directed)
                edges[v].add(u);
        }

        public List<Integer> getEdgesFrom(int i) {
            if (i < 0 || i >= V)
                throw new IllegalArgumentException("Argument must be in [0, V).");
            return this.edges[i];
        }

    }
}

