import java.util.*;

public class Main {
    public static void main(String[] args) {
    	Scanner scan = new Scanner(System.in);
		int n = scan.nextInt();
		List<String> birthday = new ArrayList<String>();
		boolean flg = false;   
		CheckDay check = new CheckDay();
		for(int i = 0 ; i < n ; i++){
			String day = scan.nextLine();
			if(check.CheckDay(birthday,day)){
				flg = true;
				break;
			}else{
				birthday.add(day);
			}
		}    	

		if(flg){
			System.out.println("Yes");
		}else{
			System.out.println("No");
		}
    }
}

class CheckDay{
	boolean CheckDay(List<String> birthday , String day){
		if(birthday.size() > 0 && birthday.indexOf(day) != -1){
			return true;
		}else{
			return false;
		}
	}
}