package yukicoder;

import java.io.BufferedReader;
import java.io.InputStreamReader;

public class Main {
	public static void main(String[] args) {
		BufferedReader buff = new BufferedReader(new InputStreamReader(System.in));

		try {
			int N = Integer.parseInt(buff.readLine());
			int[] num = new int[N];
			String[] box = buff.readLine().split(" ");
			for (int i = 0; i < N; ++i) {
				num[i] = Integer.parseInt(box[i]);
			}
			for (int i = 0; i < N / 2 + 1; ++i) {
				for (int j = i + 1; j < N; ++j) {
					if (num[i] > num[j]) {
						int sw = num[i];
						num[i] = num[j];
						num[j] = sw;
					}
				}
			}

			double ans = 0;
			if (N % 2 == 0) {
				ans = (num[N / 2 - 1] + num[N / 2]) / 2d;
			} else {
				ans = num[N / 2];
			}

			System.out.println(ans);

		} catch (Exception e) {
			e.getStackTrace();
		}
	}
}