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

int main() {
  int n;
  cin >> n;
  int a[n];
  for (auto& i : a) cin >> i;
  sort(a, a + n);
  if (n & 1) {
    cout << a[n / 2] << endl;
  } else {
    cout << (a[n / 2 - 1] + a[n / 2]) / 2.0 << endl;
  }
}