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

using namespace std;

int main(){
	vector<double> v;
	int n,d;
	cin >> n;
	for (int i = 0; i < n; i++){
		cin >> d;
		v.push_back(d);
	}
	sort(v.begin(), v.end());
	if (n % 2 == 1){
		n /= 2;
		cout << v[n] << endl;
	}
	else{
		n /= 2;
		cout << (v[n] + v[n - 1]) / 2 << endl;
	}
	return 0;
}