import java.util.Scanner;

public class Main{

	static Scanner s=new Scanner(System.in);

	public static void main(String __[]){
		input();
		solve();
	}

	private static void input(){
	}

	private static void solve(){
		int[] in=new int[s.nextInt()];
		for(int i=0;i<in.length;i++)
			in[i]=s.nextInt();
		System.out.println(getMedian(in));
	}
	public static double getMedian(int[]/*SORTED ARRAY*/ in) {
		if(in.length%2==0) {
			return ((double)in[in.length/2]+in[in.length/2-1])/2;
		}else {
			return in[in.length/2+1];
		}
	}
}