#include<bits/stdc++.h>
#pragma GCC optimize("Ofast")
//#pragma GCC target("avx2")
#pragma GCC optimize("unroll-loops")
using namespace std;
//#include<boost/multiprecision/cpp_int.hpp>
//#include<boost/multiprecision/cpp_dec_float.hpp>
//namespace mp=boost::multiprecision;
//#define mulint mp::cpp_int
//#define mulfloat mp::cpp_dec_float_100
struct __INIT{__INIT(){cin.tie(0);ios::sync_with_stdio(false);cout<<fixed<<setprecision(15);}} __init;
#define INF (1<<30)
#define LINF (lint)(1LL<<56)
#define endl "\n"
#define rep(i,n) for(lint (i)=0;(i)<(n);(i)++)
#define reprev(i,n) for(lint (i)=(n-1);(i)>=0;(i)--)
#define flc(x) __builtin_popcountll(x)
#define pint pair<int,int>
#define pdouble pair<double,double>
#define plint pair<lint,lint>
#define fi first
#define se second
#define all(x) x.begin(),x.end()
#define vec vector<lint>
#define nep(x) next_permutation(all(x))
typedef long long lint;
int dx[8]={1,1,0,-1,-1,-1,0,1};
int dy[8]={0,1,1,1,0,-1,-1,-1};
const int MAX_N=3e5+5;
template<class T>bool chmax(T &a,const T &b){if(a<b){a=b;return 1;}return 0;}
template<class T>bool chmin(T &a,const T &b){if(b<a){a=b;return 1;}return 0;}
//vector<int> bucket[MAX_N/1000];
constexpr lint MOD=1000000007;
//constexpr int MOD=998244353;
/*#include<atcoder/all>
using namespace atcoder;
typedef __int128_t llint;*/

int main(void){
    int N;
    cin >> N;
    lint A[N];
    rep(i,N) cin >> A[i];
    sort(A,A+N);
    lint sum[N+1]={};
    rep(i,N) sum[i+1]=sum[i]+A[i];
    double ans=LINF;
    rep(i,N){
        double use=(double)A[i]/2;
        use*=N;
        double over=(sum[N]-sum[i+1]);
        over-=(N-1-i)*A[i];
        ans=min(ans,use+over);
    }
    cout << ans/N << endl;
}
#include <bits/stdc++.h>
using namespace std;

int main()
{
  int n;
  cin >> n;
  double a[n];
  for(int i=0;i<n;i++){
  	cin >> a[i];
  }
  sort(a,a+n);
  double x = a[n / 2] / 2;
  double exp=0;
  for(int i=0;i<n;i++){
    exp += a[i] - min(a[i], 2*x);
  }
  exp /= n;
  exp += x;
  cout << fixed << setprecision(10) << exp << endl;
 
  return 0;
}