#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 = n-1;j>i;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;
}