#include<iostream>
#include<vector>
#include<algorithm>
using namespace std;
int main() {
	int N;

	cin >> N;
	int b = N / 2;
	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[b] + a[b - 1]) / 2 << "\n";
	}else{
		cout << a[b];
	}
	return 0;
}