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import java.util.*;
import java.io.*;
import java.text.*;
public class Solution{
    static final long mod = (long)1e9+7, IINF = (long)1e18;
    static int MAX = (int)1e6+1, L = 31;
    static FastReader in;
    static PrintWriter out;
    static boolean multipleTC = false;
    public static void main(String[] args) throws Exception{
        in = new FastReader();
        out = new PrintWriter(System.out);
        for(int tc = 1, tt = (multipleTC)?ni():1; tc<=tt; tc++)solve(tc);
        out.flush();
        out.close();
    }
    
    static void solve(int tc){
        int n = ni(), m = ni();
        boolean yes = true;
        boolean[][] grid = new boolean[n][m];
        for(int i = 0; i< n; i++){
            String s = n();
            for(int j = 0; j< m; j++)grid[i][j] = s.charAt(j) == '#';
        }
        boolean[] row = new boolean[n], col = new boolean[m];
        for(int i = 0; i< n; i++){
            for(int j = 0; j< m; j++){
                if(grid[i][j]){
                    if(row[i] || col[j])yes = false;
                    ArrayList<Integer> r = new ArrayList<>(), c = new ArrayList<>();
                    for(int k = i; k< n; k++)if(grid[k][j])r.add(k);
                    for(int k = j; k< m; k++)if(grid[i][k])c.add(k);
                    for(int k:r)for(int l:c)if(!grid[k][l])yes = false;else grid[k][l] = false;
                    for(int k:r)row[k] = true;
                    for(int k:c)col[k] = true;
                }
            }
        }
        pn((yes)?"Yes":"No");
    }
    
    
    
    static void p(Object o){
        out.print(o);
    }
    
    static void pn(Object o){
        out.println(o);
    }
    
    static void pni(Object o){
        out.println(o);
        out.flush();
    }
    
    static String n(){
        return in.next();
    }
    
    static String nln(){
        return in.nextLine();
    }
    
    static int ni(){
        return Integer.parseInt(in.next());
    }
    
    static long nl(){
            return Long.parseLong(in.next());
    }
    
    static double nd(){
        return Double.parseDouble(in.next());
    }
    
    static class FastReader{
        BufferedReader br;
        StringTokenizer st;
        public FastReader(){
            br = new BufferedReader(new InputStreamReader(System.in));
        }
        
        public FastReader(String s) throws Exception{
            br = new BufferedReader(new FileReader(s));
        }
 
        String next(){
            while (st == null || !st.hasMoreElements()){
                try{
                    st = new StringTokenizer(br.readLine());
                }catch (IOException  e){
                    e.printStackTrace();
                }
            }
            return st.nextToken();
        }
 
        String nextLine(){
            String str = "";
            try{
                str = br.readLine();
            }catch (IOException e){
                e.printStackTrace();
            }
            return str;
        }
    }
} 