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import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.StringTokenizer;

public class Main {
        static int n , m ; 
        static String g[][] ;
    public static void main(String[] args) {
        FastReader read = new FastReader();
         n  =read.nextInt() ; 
         m = read.nextInt() ; 
        g = new String[n][m];
        for (int i = 0; i < n; i++) {
            String s = read.nextLine(); 
            g[i] = s.split("");
        }
        for (int i = 0; i < n; i++) {
            for (int j = 0; j < m; j++) {
                  if(g[i][j].equals("#")){
                      if(!check(i,j))
                      {
                          System.out.println("No");
                          return;
                      }
                      else {
                          break;
                      }
                  }
            }
        }
        System.out.println("Yes");
    }
    static boolean check( int i,int j){
        boolean idxR[] = new boolean[m];
  
        for (int c = j; c < m; c++) {
             if(g[i][c].equals("#")){
                 idxR[c] = true;
             }
        }
        
        for (int k = j; k < m; k++) {
            if(idxR[k]){
                for (int l = i; l < n; l++) {
                    if(g[l][k].equals("#")){
                        if (!checkRow(idxR, l))
                            return false; 
                    }
                }
            }
        }
        return true ;
    }
    
    static boolean checkRow(boolean idxR[] , int r){
        for (int i = 0; i < m; i++) {
            if(g[r][i].equals("#") && idxR[i] == false ){
                return false; 
            }
            else if (g[r][i].equals(".") && idxR[i]){
                return false; 
            } 
                
        }
        return true; 
    }
}


class FastReader {

    BufferedReader br;
    StringTokenizer st;

    public FastReader() {
        br = new BufferedReader(new InputStreamReader(System.in));
    }

    String next() {
        while (st == null || !st.hasMoreElements()) {
            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());
    }

    String nextLine() {
        String str = "";
        try {
            str = br.readLine();
        } catch (IOException e) {
            e.printStackTrace();
        }
        return str;
    }
}
