import java.util.*;

public class Main{
    public static void main(String[] args){
       Scanner sc = new Scanner(System.in);
       int num = sc.nextInt();
       int[] line = new int[num];
       for(int i=0;i<num;i++){
           line[i] = sc.nextInt();
       }
       Arrays.sort(line);
       if(num%2==0)System.out.println((line[num/2]+line[num/2-1])/2.0);
       else System.out.println(line[num/2]);
    }
}