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

class Tyuo{
	public static void main(String args[]){
		Scanner s = new Scanner(System.in);
		int N = s.nextInt();
		int a[] = new int[N];
		for(int i = 0; i < N; i++){
			a[i] = s.nextInt();
		}
		Arrays.sort(a);
		if(N % 2 != 0){
			System.out.println(a[N/2]);
		}else{
			System.out.println((a[(N/2)-1] + a[N/2]) / 2.0);
		}
}
}