using System;
using System.Collections.Generic;
public class Program
{
public static void Main()
{
string temp="SHUKLAA";
Dictionary<char,bool> chars=new Dictionary<char,bool>();
foreach(char ch in temp)
{
if(!chars.ContainsKey(ch))
chars.Add(ch,true);
else
Console.WriteLine(string.Format("duplicate character is {0}",ch))
}
}
}
;