#include<iostream>
#include<algorithm>

using namespace std;

int main(){

  int n;
  double to;
  cin >> n;
  int a[n];

  for(int i = 0; i < n; i++)
    cin >> a[i];

 

  for(int i = 0; i < n;i++){
    
    for(int j = i;j<n-1;j++){
      if(a[j] > a[j+1]){
        swap(a[j],a[j+1]);
      }}}


    if(n%2==1)
      to = a[(n/2)];
    else
      to = (a[n/2] + a[n/2-1]) / 2.0;

      cout << to << endl;
}