import java.util.*;

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