#include <iostream>
#include <algorithm>
#include <vector>
using namespace std;
static const int N = 1000;
int main(void){
  int n;
  int a[N];
  cin >> n;
  vector<int> 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)] << endl;
  }else{
    // cout << "n/2:" << V[n/2-1] << "n/2+1:" << V[n/2] << endl;
    cout << (V[n/2-1] + V[n/2])/2.0 << endl;
  }
}