#include "bits/stdc++.h"
using namespace std;

int main() {
	int N;
	double A[1000];
	cin >> N;
	for (int i = 0; i < N; i++) {
		cin >> A[i];
	}
	sort(A, A + N);
	if (N % 2 == 1) cout << A[(N - 1) / 2];
	else {
		double X = A[N / 2 - 1] + A[N / 2];
		cout << X / 2;
	}
}