#include <algorithm>
#include <iostream>
#include <iomanip>
#include <cstring>
#include <string>
#include <vector>
#include <queue>
#include <cmath>
#include <stack>
#include <set>
#include <map>
typedef long long ll;
typedef unsigned int uint;
using namespace std;

int main() {
	int n;
	cin >> n;
	int a[n];
	for (int i = 0; i < n; i++) {
		cin >> a[i];
	}

	sort(a, a + n);


	float megian;
	if (n % 2 == 0) {
		megian = (a[n / 2] + a[n / 2 - 1]) / 2.0f;
	} else
		megian = (a[n / 2]);

	cout << megian << endl;
}