#line 1 "main.cpp"
#include <atcoder/modint>
#include <iostream>

using namespace std;

using mint = atcoder::modint998244353;

void solve() {
    int n;
    cin >> n;

    mint ans = 0;
    for (int i = 0; i < n; ++i) {
        int a;
        cin >> a;
        mint x = a;

        ans += x * (mint(2).pow(n - 1) +
                    mint(2).pow(n - 2) * i);
    }

    cout << ans.val() << "\n";
}

int main() {
    cin.tie(nullptr);
    ios::sync_with_stdio(false);

    solve();

    return 0;
}