#include<bits/extc++.h>
using namespace __gnu_pbds;
using namespace std;
using ll = long long;
template <class T> constexpr auto NL(T) -> T {return std::numeric_limits<T>::max();}
template <class T> using Tree = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
#define pb push_back
template<class T>
constexpr T power(T a, ll b) {
    T res = 1;
    for (; b; b /= 2, a *= a) {
        if (b % 2) {
            res *= a;
        }
    }
    return res;
}

template<ll P>
struct MInt {
    ll x;
    constexpr MInt() : x{} {}
    constexpr MInt(ll x) : x{norm(x % P)} {}

    constexpr ll norm(ll x) const {
        if (x < 0) {
            x += P;
        }
        if (x >= P) {
            x -= P;
        }
        return x;
    }
    constexpr ll val() const {
        return x;
    }
    explicit constexpr operator ll() const {
        return x;
    }
    constexpr MInt operator-() const {
        MInt res;
        res.x = norm(P - x);
        return res;
    }
    constexpr MInt inv() const {
        assert(x != 0);
        return power(*this, P - 2);
    }
    constexpr MInt &operator*=(MInt rhs) {
        x = 1LL * x * rhs.x % P;
        return *this;
    }
    constexpr MInt &operator+=(MInt rhs) {
        x = norm(x + rhs.x);
        return *this;
    }
    constexpr MInt &operator-=(MInt rhs) {
        x = norm(x - rhs.x);
        return *this;
    }
    constexpr MInt &operator/=(MInt rhs) {
        return *this *= rhs.inv();
    }
    friend constexpr MInt operator*(MInt lhs, MInt rhs) {
        MInt res = lhs;
        res *= rhs;
        return res;
    }
    friend constexpr MInt operator+(MInt lhs, MInt rhs) {
        MInt res = lhs;
        res += rhs;
        return res;
    }
    friend constexpr MInt operator-(MInt lhs, MInt rhs) {
        MInt res = lhs;
        res -= rhs;
        return res;
    }
    friend constexpr MInt operator/(MInt lhs, MInt rhs) {
        MInt res = lhs;
        res /= rhs;
        return res;
    }
    friend constexpr std::istream &operator>>(std::istream &is, MInt &a) {
        ll v;
        is >> v;
        a = MInt(v);
        return is;
    }
    friend constexpr std::ostream &operator<<(std::ostream &os, const MInt &a) {
        return os << a.val();
    }
    friend constexpr bool operator==(MInt lhs, MInt rhs) {
        return lhs.val() == rhs.val();
    }
    friend constexpr bool operator!=(MInt lhs, MInt rhs) {
        return lhs.val() != rhs.val();
    }
};

template<ll V, ll P>
constexpr MInt<P> CInv = MInt<P>(V).inv();

constexpr ll P = 998244353;
// constexpr ll P = 1e9+7;
using Z = MInt<P>;

struct Comb {
    ll n;
    std::vector<Z> _fac;
    std::vector<Z> _invfac;
    std::vector<Z> _inv;

    Comb() : n{0}, _fac{1}, _invfac{1}, _inv{0} {}
    Comb(ll n) : Comb() {
        init(n);
    }

    void init(ll m) {
        if (m <= n) return;
        _fac.resize(m + 1);
        _invfac.resize(m + 1);
        _inv.resize(m + 1);

        for (ll i = n + 1; i <= m; i++) {
            _fac[i] = _fac[i - 1] * i;
        }
        _invfac[m] = _fac[m].inv();
        for (ll i = m; i > n; i--) {
            _invfac[i - 1] = _invfac[i] * i;
            _inv[i] = _invfac[i] * _fac[i - 1];
        }
        n = m;
    }

    Z fac(ll m) {
        if (m > n) init(2 * m);
        return _fac[m];
    }
    Z invfac(ll m) {
        if (m > n) init(2 * m);
        return _invfac[m];
    }
    Z inv(ll m) {
        if (m > n) init(2 * m);
        return _inv[m];
    }
    Z binom(ll n, ll m) {
        if (n < m || m < 0) return 0;
        return fac(n) * invfac(m) * invfac(n - m);
    }
} comb;
ll costp[1 << 22];
Z two[30];
void solve(void) {
    ll n;
    cin >> n;
    two[0] = 1;
    for (ll i = 1; i <= 26; i++) two[i] = two[i - 1] * 2;
    std::vector<ll> cost(n);
    ll pp = (1 << n) - 1;
    for (ll i = 0; i < n; i++)cin >> cost[i];
    for (ll j = 2; j < (1 << n); j++) {
        costp[j] = NL(1LL) / 2;
    }

    for (ll j = 0; j < (1 << n); j++) {
        for (ll i = 0; i < n - 1; i++) {
            ll now = (j << (i + 1));
            now |= ((now >> (n)));
            now |= 1;
            now |= (1 << (i + 1));
            now &= pp;
            // get(now);
            // cout<<"\n";
            costp[now] = min(costp[now], costp[j] + cost[i + 1]);
        }
    }
    Z ans = 0;
    for (ll i = 1; i < (1 << (n)); i++) {
        Z now = 0;
        ll te = 0;
        for (ll j = 0; j < n; j++) {
            if (i >> j & 1) {
                now += two[j];
                if (j == 0)continue;
                te |= (1LL << (n - j));
            }
        }

        te |= 1;
        ans = ans + now * costp[te];
    }
    cout << ans;
}
int main() {
    ios::sync_with_stdio(false); cin.tie(nullptr); cout.tie(nullptr);
    ll t = 1;
    // cin>>t;
    while (t--)
        solve();
    return 0;
}