Envío 2833

Código

import java.util.Scanner;

public class Main {

    public static void main(String[] args) {

        //input dimensiones
        String cadena = leer.nextLine().trim();

        int count = 0;
        int i = 0;
        int k = 0;
        boolean continuar = true;
        //String borde = "";
        boolean finalizar = false;

        while (k < cadena.length() && !finalizar) {
            continuar=true;
            i=k+1;
            while (i < cadena.length() && !finalizar) {
                if (cadena.charAt(k) == cadena.charAt(i)) {
                    finalizar=true;    
                } 
                i++;
            }
            k++;
        }
        
        if(finalizar){
            System.out.println("yes");
        }else{
            System.out.println("no");
        }

    }
    
     public static Scanner leer = new Scanner(System.in);
}