#include <iostream>
#include <vector>
#include <algorithm>

using namespace std;

int main() {
	vector<int> x;
	int n;
	float med;

	cin >> n;
	for (int i = 0; i < n; i++) {
		int temp;
		cin >> temp;
		x.push_back(temp);
	}

	sort(x.begin(), x.end());

	if (n % 2 == 1) {
		cout << x[n / 2] << endl;
	}
	else {
		med = (x[n / 2 - 1] + x[n / 2]) / 2.0;

		cout << med << endl;
	}

	return 0;
}