#include <iostream>
#include <vector>
#include <cstdio>
#include <sstream>
#include <map>
#include <string>
#include <algorithm>
#include <queue>
#include <cmath>
#include <set>
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());
	if(n&1){
		cout << a[n/2] << endl;
	}else{
		cout << (a[n/2] + a[n/2-1]) *0.5 << endl;
	}
	return 0;
}