#include <bits/stdc++.h>
using namespace std;

int main() {
	long n;
	cin >> n;
	vector<long> a(n);
	for(int i=0; i<n; i++){
		cin >> a[i];
	}
	sort(a.begin(),a.end());
	if(n%2==0){
		double ans=(a[n/2]+a[n/2-1])/2.0;
		cout << ans << endl;
	}else{
		cout << a[n/2] << endl;
	}
	return 0;
}