/* package whatever; // don't place package name! */
 
import java.util.*;
import java.lang.*;
import java.io.*;
 
/* Name of the class has to be "Main" only if the class is public. */
class Ideone
{
	public static void main (String[] args) throws java.lang.Exception
	{
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		int k = Integer.parseInt(br.readLine());
		int[] arr = new int[k];
		String line = br.readLine();
		String[] nums = line.split(" ");
		for(int i = 0; i < k;i++)
			arr[i] = Integer.parseInt(nums[i]);
		Arrays.sort(arr);
		int total = 0;
		for(int i = k-2, j = 1; j <= k/3 ; i-= 2, j++) {
			total += arr[i];
 
 
		}
	System.out.println(total);
	}
}

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NgoxIDUgNCAyIDMgNg==

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