E6.2 part D

import java.util.*;


public class E62 {

    public static void main(String[] args) {
        Scanner s = new Scanner(System.in);
        System.out.println("enter your input");



        String input = s.nextLine();


        for(int i=0; i < (input.length() - 2); i+=2)
        {
            char first = input.charAt(i);
            char second = input.charAt(i+2);
            if(first == second )
            {
                System.out.print(Character.toString(first));
            }


        }


    }

}