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/* package codechef; // don't place package name! */

import java.util.*;
import java.lang.*;
import java.io.*;

/* Name of the class has to be "Main" only if the class is public. */
public class Main
{
    static int count = 0;
	public static void main (String[] args) throws java.lang.Exception
	{
		Scanner in = new Scanner(System.in);
		int n = in.nextInt();
		int m = in.nextInt();
		String[] grid = new String[n];
		for(int i=0;i<n;i++){
		   grid[i]= in.next();
		}
		System.out.println(possibleValidOperations(grid,n,m)?"Yes":"No");
	}
	public static boolean possibleValidOperations(String[] grid,int n,int m){
	    int[] row= new int[n+1];
	    int[] col= new int[m+1];
	    int iter=0;
	    List<Integer> l = new ArrayList<Integer>();
	    for(int i=0;i<n;i++){
	        iter++;
	        for(int j=0;j<m;j++){
	            if(grid[i].charAt(j)=='#'&&row[i]==0&&col[j]==0){
	                row[i]=iter;
	                col[j]=iter;
	                l.add(j);
	            }else if(grid[i].charAt(j)=='#'&&row[i]!=0&&col[j]==0){
	                col[j]=row[i];
	                l.add(j);
	            }else if(grid[i].charAt(j)=='#'&&row[i]==0&&col[j]!=0){
	                row[i]=col[j];
	        
	            }
	        }
	        for(Integer j:l){
	            for(int i2=0;i2<n;i2++){
	               if(grid[i2].charAt(j)=='#'&&row[i2]==0)
	                   row[i2]=iter;
	            }
	        }
	        
	    }
	    for(int i=0;i<grid.length;i++){
	        for(int j=0;j<grid[0].length();j++){
	            if(grid[i].charAt(j)=='.'&&row[i]==col[j]&&row[i]!=0&&row[j]!=0) return false;
	        }
	    }
	    
	    return true;
	}
	
	}

