#include <iostream>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <string>
#include <sstream>
#include <complex>
#include <algorithm>
#include <functional>
#include <vector>
#include <stack>
#include <queue>
#include <set>
#include <map>
#include <cmath>
#include <cassert>
#include <fstream>
#define REP(i,n) for(int i=0;i<n;i++)
#define FOR(a,b) for(:a<b;a++)
#define SSTR( x ) static_cast< std::ostringstream & >( \
        ( std::ostringstream() << std::dec << x ) ).str()
#define ALL(s) (s).begin(), (s).end()
using namespace std;
typedef long long unsigned int llu;
typedef long long ll;

int main (){
  int n;
  while (cin >> n){
    double ans;
    vector<int> a;
    REP(i,n){
      int ma;
      cin >> ma;
      a.push_back(ma);
    }

    sort(ALL(a));

    int size = n;
    if(n%2 == 0){
      ans = (double)(a[n/2-1] + a[n/2])/(double)2;
    }else{
      ans = a[n/2];
    }
    
    cout << ans << endl;
    a.clear();
  }
  return 0;
}