#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;
int main() {
	int n;
	cin >> n;
	vector<int> a(n);
	for (int i = 0; i < n; i++)cin >> a[i];
	sort(a.begin(), a.end());
	
	if (n % 2 == 0)cout << (double)(a[n / 2 - 1] + a[n / 2]) / 2 << endl;
	else cout << a[n / 2] << endl;
}