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

public class Median {

	public static void main(String[] args) {
		Scanner s = new Scanner(System.in);
		int N = s.nextInt();
		double[] A = new double[N];
		for(int i = 0;i < N ;i++){
			A[i] = s.nextDouble();
		}
		s.close();
		Arrays.sort(A);

		double med = 0;
		if(N % 2 == 1){
			med = (double)A[(N-1)/2];
		}else{
			med = (double)(A[N/2-1] + A[N/2]) /2;
		}
		System.out.println(String.format("%.1f",med));
	}

}