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


public class Main {

    void solve(){
        int n=ni(),m=ni();
        char s[][]=new char[n][m];
        for(int i=0;i<n;i++) s[i]=ns().toCharArray();
        char ans[][]=new char[n][m];
        ArrayList<Integer> vr[]=new ArrayList[n];
        ArrayList<Integer> vc[]=new ArrayList[m];
        for(int i=0;i<n;i++) vr[i]=new ArrayList<>();

        for(int i=0;i<m;i++){
            vc[i]=new ArrayList<>();
        }
        for(int i=0;i<n;i++){
            for(int j=0;j<m;j++){
                if(s[i][j]=='#') vr[i].add(j);
            }
        }
        for(int j=0;j<m;j++){
            for(int i=0;i<n;i++){
                if(s[i][j]=='#'){
                    vc[j].add(i);
                }
            }
        }
        for(int j=0;j<m;j++){
                for(int id=1;id<vc[j].size();id++){
                    int r1=vc[j].get(id),r2=vc[j].get(id-1);
                    if(vr[r1].size()!=vr[r2].size()){
                        pw.println("No");
                        return;
                    }
                    for(int i=0;i<vr[r1].size();i++){
                        if(vr[r1].get(i)!=vr[r2].get(i)){
                            pw.println("No");
                            return;
                        }
                    }
                }
        }
        pw.println("Yes");

    }




    long M=(long)1e9+7;
    InputStream is;
    PrintWriter pw;
    String INPUT = "";
    void run() throws Exception {
        is = INPUT.isEmpty() ? System.in : new ByteArrayInputStream(INPUT.getBytes());
        pw = new PrintWriter(System.out);
        long s = System.currentTimeMillis();
        solve();
        pw.flush();
        if(!INPUT.isEmpty())tr(System.currentTimeMillis()-s+"ms");
    }

    public static void main(String[] args) throws Exception { new Main().run(); }

    private byte[] inbuf = new byte[1024];
    public int lenbuf = 0, ptrbuf = 0;

    private int readByte() {
        if(lenbuf == -1)throw new InputMismatchException();
        if(ptrbuf >= lenbuf){
            ptrbuf = 0;
            try { lenbuf = is.read(inbuf); } catch (IOException e) { throw new InputMismatchException(); }
            if(lenbuf <= 0)return -1;
        }
        return inbuf[ptrbuf++];
    }

    private boolean isSpaceChar(int c) { return !(c >= 33 && c <= 126); }
    private int skip() { int b; while((b = readByte()) != -1 && isSpaceChar(b)); return b; }

    private double nd() { return Double.parseDouble(ns()); }
    private char nc() { return (char)skip(); }

    private String ns() {
        int b = skip();
        StringBuilder sb = new StringBuilder();
        while(!(isSpaceChar(b))){ // when nextLine, (isSpaceChar(b) && b != ' ')
            sb.appendCodePoint(b);
            b = readByte();
        }
        return sb.toString();
    }

    private char[] ns(int n) {
        char[] buf = new char[n];
        int b = skip(), p = 0;
        while(p < n && !(isSpaceChar(b))){
            buf[p++] = (char)b;
            b = readByte();
        }
        return n == p ? buf : Arrays.copyOf(buf, p);
    }

    private char[][] nm(int n, int m) {
        char[][] map = new char[n][];
        for(int i = 0;i < n;i++)map[i] = ns(m);
        return map;
    }

    private int[] na(int n) {
        int[] a = new int[n];
        for(int i = 0;i < n;i++)a[i] = ni();
        return a;
    }

    private int ni() {
        int num = 0, b;
        boolean minus = false;
        while((b = readByte()) != -1 && !((b >= '0' && b <= '9') || b == '-'));
        if(b == '-'){
            minus = true;
            b = readByte();
        }

        while(true){
            if(b >= '0' && b <= '9'){
                num = num * 10 + (b - '0');
            }else{
                return minus ? -num : num;
            }
            b = readByte();
        }
    }

    private long nl() {
        long num = 0;
        int b;
        boolean minus = false;
        while((b = readByte()) != -1 && !((b >= '0' && b <= '9') || b == '-'));
        if(b == '-'){
            minus = true;
            b = readByte();
        }

        while(true){
            if(b >= '0' && b <= '9'){
                num = num * 10 + (b - '0');
            }else{
                return minus ? -num : num;
            }
            b = readByte();
        }
    }

    private void tr(Object... o) { if(INPUT.length() > 0)System.out.println(Arrays.deepToString(o)); }
}