#include <iostream>
#include <algorithm>
using namespace std;


int main() {
    int n;
    cin >> n;
    int a[n];
    float result;n%2==1 ? a[n/2+1] : float((a[n/2] + a[n/2+1]) / 2);
    for (int i=0; i<n; i++){
        cin >> a[i];
    }

    sort(a, a+n);
    result = n%2==1 ? a[n/2] : (float)(a[n/2] + a[n/2-1]) / 2;
    cout << result << endl;
}