#include <iostream>
#include <stdio.h>
#include <math.h>
#include <vector>
#include <algorithm>
using namespace std;

int main(){
	int n;
	cin >> n;
	vector<int> a;
	for(int i=0;i<n;i++) {
		int tmp;
		cin >> tmp;
		a.push_back(tmp);
	}
	sort(a.begin(),a.end());
	double ans=0.0;
	if(a.size()%2 == 0) ans = (double)(a[a.size()/2-1]+a[a.size()/2])/2;
	else ans = a[a.size()/2];

	cout << ans << endl;


}