package yuki_coder;

import java.util.Arrays;
import java.util.Scanner;

public class No_275 {
public static void main(String[] args) {
	Scanner sc = new Scanner(System.in);
	int n = sc.nextInt();
	int[] a = new int[n];
	for(int i=0; i<a.length; i++){
		a[i] = sc.nextInt();
	}
	Arrays.sort(a);
	if(n%2==1){
		int b = (n+1)/2;
		System.out.println(a[b-1]);
	}else{
		double b = ((n+1.0)/2.0);
		int c = (int)((b - 0.5)-1);
		int d = (int)((b + 0.5)-1);
		double e = (a[c] + a[d])/2.0;
		System.out.println(e);
}
	}
}