import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.Arrays;

import static java.lang.System.in;


public class Main {
    public static void main(String[] args) throws IOException {
        BufferedReader reader = new BufferedReader(new InputStreamReader(in));
        int N = Integer.parseInt(reader.readLine());
        int[] table = new int[N];
        String[] inputs = reader.readLine().split(" ");
        for (int i = 0; i < N; i++) {
            table[i] = Integer.parseInt(inputs[i]);
        }
        Arrays.sort(table);
        if (N % 2 == 0) {
            int left = table[(N/2)-1];
            int right = table[(N/2)];
            System.out.println((left + right) / 2.0);
        } else {
            System.out.println(table[(N/2)]);
        }
    }
}