#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());
	cout << ((n % 2 == 0) ? (a[n/2-1] + a[n/2]) / 2.0 : a[(n-1)/2]) << endl;

	return 0;
}