#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;
using ll = long long;

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