#include <bits/stdc++.h>
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 % 2 == 0)
    {
        cout << (A[N / 2] + A[N / 2 - 1]) / (double)2;
    }
    else
    {
        cout << A[N / 2];
    }
}