using System;

public class Program

{

    public static void Main()

    {

        Console.WriteLine(unique("HelloWorld"));

    }

    public static bool unique(string s){

        bool[] a = new bool[128];

        for (int i = 0; i< s.Length-1;i++){

        int t = s[i];

            Console.WriteLine(a[t]);

            if(a[t]) {

                return false;

            }

            a[t] = true;

        }

        return true;

    }

}