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import java.io.*;
import java.util.*;
 
 
public class test {
    static boolean DEBUG_FLAG = false;
    int INF = (int)1e9;
    long MOD = 1000000007;
    
    static void debug(String s) {
        if(DEBUG_FLAG) {
            System.out.print(s);
        }
    }

    
    
    
    void solve(InputReader in, PrintWriter out) throws IOException {
        int n = in.nextInt();
        int m = in.nextInt();
        char[][] s = new char[n][];
        for(int i=0; i<n; i++) {
            s[i] = in.next().toCharArray();
        }
        boolean[][] vis = new boolean[n][m];
        int[][] a = new int[n+1][m+1];
        ArrayList<Integer> r = new ArrayList<>();
        ArrayList<Integer> c = new ArrayList<>();
        boolean ok = true;
        outer: for(int i=0; i<n; i++) {
            for(int j=0; j<m; j++) {
                if(s[i][j]!='#') continue;
                if(vis[i][j]) continue;
                r.add(i);
                for(int k=0; k<r.size(); k++) {
                    int rv = r.get(k);
                    for(int l=0; l<m; l++) {
                        if(s[rv][l]!='#') continue;
                        if(vis[rv][l]) {ok = false; break outer;}
                        if(!c.contains(l)) {
                            c.add(l);
                            for(int d=0; d<n; d++) {
                                if(s[d][l]!='#') continue;
                                if(vis[d][l]) {ok = false; break outer;}
                                r.add(d);
                            }
                        }
                    }
                }
                for(int x: r) {
                    for(int y: c) {
                        a[x][y] = 1;
                        vis[x][y] = true;
                    }
                }
                r = new ArrayList<>();
                c = new ArrayList<>();
            }
        }
        sec: for(int i=0; i<n; i++) {
            for(int j=0; j<m; j++) {
                if(a[i][j]==1 && s[i][j]!='#') {
                    ok = false;
                    break sec;
                }
            }
        }
//        for(int i=0; i<n; i++) {
//            for(int j=0; j<m; j++) {
//                out.print(a[i][j]);
//            }
//            out.println();
//        }
        if(ok) out.println("Yes");
        else out.println("No");
    }
    
    
    public static void main(String[] args) throws IOException {
        if(args.length>0 && args[0].equalsIgnoreCase("d")) {
            DEBUG_FLAG = true;
        }
        InputReader in = new InputReader();
        PrintWriter out = new PrintWriter(System.out);
        int t = 1;//in.nextInt();
        long start = System.nanoTime();
        while(t-- >0) {
            new test().solve(in, out);
        }
        long end = System.nanoTime();
        debug("\nTime: " + (end-start)/1e6 + " \n\n");
        out.close();
    }
    
    static class InputReader {
        static BufferedReader br;
        static StringTokenizer st;
    
        public InputReader() {
            br = new BufferedReader(new InputStreamReader(System.in));
        }
        
        String next() {
            while (st == null || !st.hasMoreTokens()) {
                try {
                    st = new StringTokenizer(br.readLine());
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            return st.nextToken();
        }
        
        int nextInt() {
            return Integer.parseInt(next());
        }
        
        long nextLong() {
            return Long.parseLong(next());
        }
        
        double nextDouble() {
            return Double.parseDouble(next());
        }
    }
}