import java.util.Arrays;
import java.util.Scanner;

public class Main{

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

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

	private static void input(){
	}
	private static void solve(){
		int n=s.nextInt(),in[]=new int[n];
		for(int i=0;i<n;i++)
			in[i]=s.nextInt();
		Arrays.sort(in);

		System.out.println(getMedian(in));
	}
	public static double getMedian(int[]/*SORTED ARRAY*/ in) {
		if(in.length%2==0) {
			return ((double)in[in.length/2-1]+in[in.length/2])/2;
		}else {
			return in[in.length/2];
		}
	}
}