#include <iostream>
#include <cstdio>
#include <string>
#include <algorithm>
#include <utility>
#include <cmath>
#include <vector>
#include <stack>
#include <queue>
#include <deque>
#include <set>
#include <unordered_set>
#include <map>
#include <tuple>
#include <numeric>
#include <functional>
using namespace std;
typedef long long ll;
typedef vector<ll> vl;
typedef vector<vector<ll>> vvl;
typedef pair<ll, ll> P;
#define rep(i, n) for(ll i = 0; i < n; i++)
#define exrep(i, a, b) for(ll i = a; i <= b; i++)
#define out(x) cout << x << endl
#define exout(x) printf("%.10f\n", x)
#define chmax(x, y) x = max(x, y)
#define chmin(x, y) x = min(x, y)
#define all(a) a.begin(), a.end()
#define rall(a) a.rbegin(), a.rend()
#define pb push_back
#define re0 return 0
const ll mod = 998244353;
const ll INF = 1e16;

const ll MAX = 10;

// a^n (mod.MOD)を求める。計算量はO(logn)
ll modpow(ll a, ll n, ll MOD = mod) {
    if(n == 0) {
        return 1;
    }
    if(n%2 == 1) {
        return (a * modpow(a, n-1, MOD))%MOD;
    }
    return (modpow(a, n/2, MOD) * modpow(a, n/2, MOD))%MOD;
}

ll inverse(ll a) {
    return modpow(a, mod - 2);
}

ll fact[MAX];  // fact[i] : iの階乗のmod
ll inv[MAX];  // inv[i] : iの逆数のmod
ll invfact[MAX];  // invfact[i] : iの階乗の逆数のmod

void init() {
    fact[0] = 1;
    inv[0] = inv[1] = 1;
    invfact[0] = 1;
    for(ll i = 1; i < MAX; i++) {
        fact[i] = i * fact[i-1] % mod;
        if(i >= 2) {
            inv[i] = mod - inv[mod % i] * (mod / i) % mod;
        }
        invfact[i] = inverse(fact[i]);
    }
}
 
int main() {
    ll n;
    cin >> n;

    vl a(n);
    rep(i, n) {
        cin >> a[i];
    }
    sort(all(a));

    if(n == 1) {
        out(a[0] * a[0] % mod);
        re0;
    }
    else if(n == 2) {
        ll ans = (a[0] * a[0] % mod + a[0] * a[1] % mod + a[1] * a[1] % mod) % mod;
        out(ans);
        re0;
    }

    ll x = a[0] + a[1];
    exrep(i, 2, n-1) {
        x += a[i] * modpow(2LL, i-1) % mod;
        x %= mod;
    }

    init();

    ll ans = a[0] * x % mod;
    exrep(i, 1, n-1) {
        x = ((x + 2*mod - (a[i-1] + a[i])) % mod * inv[2] % mod + a[i]) % mod;
        ans += a[i] * x;
        ans %= mod;
    }

    out(ans);
    re0;
}
 
    #pragma GCC optimize ("-O3")
    #include <bits/stdc++.h>  
     
    using namespace std;
     
    typedef long long ll;
    typedef long double ld;
    typedef pair<int,int> p32;
    typedef pair<ll,ll> p64;
    typedef pair<double,double> pdd;
    typedef vector<ll> v64;
    typedef vector<int> v32;
    typedef vector<vector<int> > vv32;
    typedef vector<vector<ll> > vv64;
    typedef vector<vector<p64> > vvp64;
    typedef vector<p64> vp64;
    typedef vector<p32> vp32;
    ll MOD = 998244353;
    #define forn(i,e) for(ll i = 0; i < e; i++)
    #define forsn(i,s,e) for(int i = s; i < e; i++)
    #define rforn(i,s) for(ll i = s; i >= 0; i--)
    #define rforsn(i,s,e) for(ll i = s; i >= e; i--)
    #define ln "\n"
    #define dbg(x) cout<<#x<<" = "<<x<<ln
    #define mp make_pair
    #define pb push_back
    #define fi first
    #define se second
    #define INF 1e18
    #define fast_cin() ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL)
    #define all(x) (x).begin(), (x).end()
    #define sz(x) ((ll)(x).size())
     
    ll mpow(ll a, ll b){
        if(b >= (MOD-1)) b %= (MOD-1);
        if(b==0) return 1;
        ll t1 = mpow(a,b/2);
        t1 *= t1;
        t1 %= MOD;
        if(b%2) t1 *= a;
        t1 %= MOD;
        return t1;
    }
     
    ll mpow(ll a, ll b, ll p){
        if(b==0) return 1;
        ll t1 = mpow(a,b/2,p);   t1 *= t1;
        t1 %= p;
        if(b%2) t1 *= a;
        t1 %= p;
        return t1;
    }
    ll modinverse(ll a, ll m){
        ll m0 = m; 
        ll y = 0, x = 1; 
        if (m == 1) return 0; 
        while (a > 1){
            ll q = a / m; 
            ll t = m; 
            m = a % m, a = t; 
            t = y; 
            y = x - q * y; 
            x = t; 
        }
        if (x < 0) x += m0; 
        return x; 
    }
    ll range(ll l, ll r){
        return l + rand()%(r-l+1);
    }
    
    double calc(double x, vector<ll>& arr)
    {
        double ans = 0;

        for(ll i=0;i<arr.size();i++)
        {
            ans += (double)(x + arr[i]);
            ans -= (double)min((double)arr[i], 2*x);
        }
        return ans;
    }
    int main()
    {
        fast_cin();
        ll n;
        cin>>n;
        vector<ll>arr(n);
        for(ll i=0;i<n;i++)cin>>arr[i];

        double l = 0, r = 1e9 + 10;
        while(r - l >= 1e-8)
        {
            double z = (r - l)/3;
            double l1 = l + z;
            double r1 = r - z;

            double a = calc(l1, arr);
            double b = calc(r1, arr);
            if(a < b)r = r1;
            else l = l1;

            if(abs(a-b) <= 1e-8)break;
            
        }

        cout<<fixed<<setprecision(10)<<calc(l, arr)/(double)n<<endl;
    }