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

using namespace std;


int main(){
  int numlen;
  int num;
  vector<int> num_v;
  cin >> numlen;
  for (int i = 0;i < numlen;i++) {
    /* code */
    cin >> num;
    num_v.push_back(num);
  }
  sort(num_v.begin(), num_v.end());
  if (num_v.size()%2){
    //cout << num_v.size()%2<< endl;
    cout << num_v[num_v.size()/2]<< endl;
  }else{
    //cout << num_v.size()/2<< endl;
    cout << (num_v[num_v.size()/2 - 1] + num_v[num_v.size()/2])/2.0 << endl;
  }
}