#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using ull = unsigned long long;
using Matrix = vector<vector<ll>>;
const int inf = 1000000000;
const ll INF = 1000000000000000000;
const ll mod = 998244353;
const ull mod_hash = (1UL << 61) - 1;
const vector<int> dx = {0, 1, 0, -1, 1, 1, -1, -1};
const vector<int> dy = {1, 0, -1, 0, 1, -1, 1, -1};

struct BinomialCoefficient {
  int N = 10100000; //maxN
  ll m; //prime
  vector<ll> fac, finv, inv;
  BinomialCoefficient(ll m) : m(m), fac(N, 1), finv(N, 1), inv(N, 1) {
    for (int i = 2; i < N; i++) {
      fac[i] = (fac[i - 1] * i) % m;
      inv[i] = (m - (inv[m % i] * (m / i)) % m);
      finv[i] = (finv[i - 1] * inv[i]) % m;
    }
  }
  ll C(int n, int k) {
    if (n < k) return 0;
    if (n < 0 || k < 0) return 0;
    return fac[n] * (finv[k] * finv[n - k] % m) % m;
  }
  ll P(int n, int k) {
    if (n < k) return 0;
    if (n < 0 || k < 0) return 0;
    return fac[n] * finv[n - k] % m;
  }
};

ll extGCD(ll a, ll b, ll &x, ll &y) {
  if (b == 0) {
    x = 1;
    y = 0;
    return a;
  }
  ll d = extGCD(b, a % b, x, y);
  swap(x, y);
  y -= a / b * x;
  return d;
}

int main(){
  int N;cin>>N;
  vector<ll> A(N);
  for (int i = 0; i < N; i++) cin>>A[i];
  BinomialCoefficient com(mod);
  ll ans = 0;
  for (int i = 0; i < N; i++) {
    ans += (((com.C(N - 1 + N - i - 1, N - 1) - com.C(N - 1 + N - i - 1, N - 1 - 1 - i)) % mod)  + mod) % mod * A[i] % mod;
    ans %= mod;
  }
  cout << ans << endl;
  return 0;
}