//#pragma GCC optimize("O3")
//#pragma GCC optimize("unroll-loops")
#include<iostream>
#include<string>
#include<cstdio>
#include<vector>
#include<cmath>
#include<algorithm>
#include<functional>
#include<iomanip>
#include<queue>
#include<ciso646>
#include<random>
#include<map>
#include<set>
#include<bitset>
#include<stack>
#include<unordered_map>
#include<unordered_set>
#include<utility>
#include<cassert>
#include<complex>
#include<numeric>
#include<array>
using namespace std;

//#define int long long
typedef long long ll;

typedef unsigned long long ul;
typedef unsigned int ui;
constexpr ll mod = 1000000007;
const ll INF = mod * mod;
typedef pair<int, int>P;
#define stop char nyaa;cin>>nyaa;
#define rep(i,n) for(int i=0;i<n;i++)
#define per(i,n) for(int i=n-1;i>=0;i--)
#define Rep(i,sta,n) for(int i=sta;i<n;i++)
#define rep1(i,n) for(int i=1;i<=n;i++)
#define per1(i,n) for(int i=n;i>=1;i--)
#define Rep1(i,sta,n) for(int i=sta;i<=n;i++)
#define all(v) (v).begin(),(v).end()
typedef pair<ll, ll> LP;
typedef double ld;
typedef pair<ld, ld> LDP;
const ld eps = 1e-8;
const ld pi = acosl(-1.0);

ll mod_pow(ll x, ll n, ll m = mod) {
	if (n < 0) {
		ll res = mod_pow(x, -n, m);
		return mod_pow(res, m - 2, m);
	}
	if (abs(x) >= m)x %= m;
	if (x < 0)x += m;
	ll res = 1;
	while (n) {
		if (n & 1)res = res * x % m;
		x = x * x % m; n >>= 1;
	}
	return res;
}
struct modint {
	ll n;
	modint() :n(0) { ; }
	modint(ll m) :n(m) {
		if (n >= mod)n %= mod;
		else if (n < 0)n = (n % mod + mod) % mod;
	}
	operator int() { return n; }
};
bool operator==(modint a, modint b) { return a.n == b.n; }
modint operator+=(modint& a, modint b) { a.n += b.n; if (a.n >= mod)a.n -= mod; return a; }
modint operator-=(modint& a, modint b) { a.n -= b.n; if (a.n < 0)a.n += mod; return a; }
modint operator*=(modint& a, modint b) { a.n = ((ll)a.n * b.n) % mod; return a; }
modint operator+(modint a, modint b) { return a += b; }
modint operator-(modint a, modint b) { return a -= b; }
modint operator*(modint a, modint b) { return a *= b; }
modint operator^(modint a, ll n) {
	if (n == 0)return modint(1);
	modint res = (a * a) ^ (n / 2);
	if (n % 2)res = res * a;
	return res;
}

ll inv(ll a, ll p) {
	return (a == 1 ? 1 : (1 - p * inv(p % a, a)) / a + p);
}
modint operator/(modint a, modint b) { return a * modint(inv(b, mod)); }
modint operator/=(modint& a, modint b) { a = a / b; return a; }
const int max_n = 1 << 1;
modint fact[max_n], factinv[max_n];
void init_f() {
	fact[0] = modint(1);
	for (int i = 0; i < max_n - 1; i++) {
		fact[i + 1] = fact[i] * modint(i + 1);
	}
	factinv[max_n - 1] = modint(1) / fact[max_n - 1];
	for (int i = max_n - 2; i >= 0; i--) {
		factinv[i] = factinv[i + 1] * modint(i + 1);
	}
}
modint comb(int a, int b) {
	if (a < 0 || b < 0 || a < b)return 0;
	return fact[a] * factinv[b] * factinv[a - b];
}
modint combP(int a, int b) {
	if (a < 0 || b < 0 || a < b)return 0;
	return fact[a] * factinv[a - b];
}

void solve() {
	int n; cin >> n;
	vector<int> a(n);
	rep(i, n)cin >> a[i];
	sort(all(a));
	vector<ll> ra(n + 1);
	rep(i, n)ra[i + 1] = ra[i] + a[i];
	ld ans = INF;
	rep(i, n) {
		//[0,i]
		//x=a[i]/2
		ld x = a[i] / 2.0;
		ld sum = x * (i + 1);
		sum -= x * (n - 1 - i);
		sum += ra[n] - ra[i + 1];
		ans = min(ans, sum / (ld)n);
	}
	ans = min(ans, ra[n] / (ld)n);
	cout << ans << "\n";
}


signed main() {
	ios::sync_with_stdio(false);
	cin.tie(0);
	cout << fixed << setprecision(10);
	//init_f();
	//init(); cout << ps.size() << "\n";
	//expr();
	//int t; cin >> t; rep(i, t)
	solve();
	return 0;
}


// #pragma GCC optimize("Ofast,unroll-loops")
// #pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,mmx,avx,avx2")
#include <bits/stdc++.h>
using namespace std;

#define ll long long
#define ull unsigned long long
#define lld long double
#define w(x) ll x;cin>>x;while(x--)
#define all(x) x.begin(), x.end()
#define lb lower_bound
#define ub upper_bound
#define iceil(n, x) (((n) + (x) - 1) / (x))
#define gcd(a,b)	__gcd(a,b)
#define lcm(a,b)	__detail::__lcm(a,b)
#define goog(tno) cout << "Case #" << tno <<": "
#define PRESS_F_TO_PAY_RESPECT ios_base::sync_with_stdio(false), cin.tie(nullptr)

void __print(int x) {cerr << x;}
void __print(long long x) {cerr << x;}
void __print(unsigned x) {cerr << x;}
void __print(unsigned long long x) {cerr << x;}
void __print(double x) {cerr << x;}
void __print(long double x) {cerr << x;}
void __print(char x) {cerr << '\'' << x << '\'';}
void __print(const string &x) {cerr << '\"' << x << '\"';}
void __print(bool x) {cerr << (x ? "true" : "false");} 
template<typename T, typename V>
void __print(const pair<T, V> &x) {cerr << '{'; __print(x.first); cerr << ','; __print(x.second); cerr << '}';}
template<typename T>
void __print(const T &x) {int f = 0; cerr << '{'; for (auto &i : x) cerr << (f++ ? "," : ""), __print(i); cerr << "}";}
void _print() {cerr << "]\n";}
template <typename T, typename... V>
void _print(T t, V... v) {__print(t); if (sizeof...(v)) cerr << ", "; _print(v...);}
#ifndef ONLINE_JUDGE
#define bug(x...) cerr << "[" << #x << "] = ["; _print(x)
#else
#define bug(x...)
#endif

ll dx[]= {-1,-1,-1,0,0,1,1,1};
ll dy[]= {-1,0,1,-1,1,-1,0,1};
const lld pi=3.1415926535897932384626433832795;
const ll INF=1e18;
const ll mod=1000000007;
const ll maxn=1e5+5;


template<typename T>
void printv(const vector<T>& v) { for(auto i:v) cout<<i<<' '; cout<<'\n'; }
template<typename T>
void printv(const vector<pair<T, T>>& v) { for(auto p:v) cout<<"("<<p.first<<","<<p.second<<"),"; cout<<'\n'; }


int main(){
    PRESS_F_TO_PAY_RESPECT;
    //freopen("input.txt","r",stdin);
    //freopen("output.txt","w",stdout);
    string x;   cin>>x;
    bool f=0;
    for(auto &i:x){
        if(i=='.'){
            f=1;
            break;
        }
    }
    if(!f){
        cout<<x<<'\n';
    }else{
        ll n=x.size();
        ll i;
        for(i=0;i<n;i++){
            if(x[i]=='.'){
                break;
            }
        }
        cout<<x.substr(0,i)<<'\n';
    }
    return 0;
}