//Normal

#define _GLIBCXX_DEBUG
#define ll long long
#include <bits/stdc++.h>
using namespace std;
using Graph = vector<vector<int>>;

void print(auto a){
  cout << a;
}

void prints(auto a){
  cout << a << " ";
}

void prints(){
  cout << " ";
}

void printl(auto a){
  cout << a << endl;
}

void printl(){
  cout << endl;
}

void fix(int n){
  cout << fixed << setprecision(n);
}

int siz(string s){
  return (int)s.size();
}

int main(){
  int N; cin >> N;
  vector<int> X(N);
  
  for(int i = 0; i < N; i++) cin >> X[i];
  
  sort(X.begin(), X.end());
  
  fix(3);
  N%2 != 0 ? printl(X[N/2]) : printl((double)(X[N/2-1]+X[N/2])/2.0);
  return 0;
}