#include <bits/stdc++.h>

using namespace std;

double A[1000];

int main()
{
    int N; cin >> N;

    for (int i = 0; i < N; ++i) cin >> A[i];

    sort(A, A + N);

    cout << (N % 2 ? A[N/2] : (A[N/2-1]+A[N/2]) / 2) << endl;
}