#include <iostream>
#include <vector>
#include <algorithm>

using namespace std;

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;
   }
  return 0;
}