import java.util.ArrayList;
import java.util.Collections;
import java.util.Scanner;

public class CenterNum {

    public static void main(String[] args) {
        
        Scanner scanner = new Scanner(System.in);
        
        int n = scanner.nextInt();
        
        ArrayList<Integer> list = new ArrayList();
        
        for(int i=0;i<n;i++){
            list.add(scanner.nextInt());
        }
        
        Collections.sort(list);
        
   
        if(list.size() % 2 == 0){
            float num = (list.get(list.size()/2 - 1) + list.get(list.size()/2)) / 2.0f;
            System.out.println(String.format("%.1f", num));
        }else{
            int num = list.get(list.size()/2);
            System.out.println(num);
        }
    }
    
}