import java.util.LinkedList;
import java.util.Scanner;

public class A000275 {

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();
		LinkedList<Integer> a = new LinkedList<>();
		for(int i=0;i<n;i++) {
			int t = sc.nextInt();
			if(i==0) {
				a.add(t);
				continue;
			}
			if(a.get(a.size()-1)<=t) {
				a.addLast(t);
				continue;
			}
			for(int j=0;j<a.size();j++) {
				if(t<a.get(j)) {
					a.add(j, t);
					break;
				}
			}
		}
		sc.close();

		if(n%2==1) {
			System.out.println(a.get(n/2));
		}else {
			System.out.println((a.get(n/2-1)+a.get(n/2))/2f);
		}

	}

}