#include <bits/stdc++.h>
using namespace std;

const int MM = 998244353;

long modpow(long a, long b, long mod) {
    if (b == 0) {
          return 1;
    }
    if ((b & 1) == 0) {
      return modpow((a * a) % mod, b >> 1, mod);
    }
    return (a * modpow(a, b - 1, mod)) % mod;
}

int main() {
  int N; cin >> N;
  vector<int> A(N+1);
  for (int i=0; i<N; i++) cin >> A[i];

  vector<long> two(N+1);
  two[0] = 1;
  for (int i=1; i<N; i++) {
    two[i] = 2*two[i-1] % MM;
  }

  vector<vector<long>> I(N+5, vector<long>(3));
  I[0][2] = modpow(6, MM-2, MM); I[0][0] = 0; I[0][1] = 0;
  I[1][0] = 1; I[1][1] = modpow(-2, MM-2, MM)+MM; I[1][2] = 0;
  for (int i=1; i<(N+1)/2; i++) {
    I[2*i+1][0] = (2*i*I[2*i-1][0] % MM) * modpow(2*i+1, MM-2, MM) % MM;
    I[2*i+1][1] = ((2*i*I[2*i-1][1] % MM) * modpow(2*i+1, MM-2, MM) - modpow(two[2*i+1], MM-2, MM)) % MM;
    if (I[2*i+1][1] < 0) I[2*i+1][1] += MM;
    I[2*i+1][2] = (2*i*I[2*i-1][2] % MM) * modpow(2*i+1, MM-2, MM) % MM;

    I[2*i][0] = ((2*i-1)*I[2*i-2][0] % MM) * modpow(2*i, MM-2, MM) % MM;
    I[2*i][1] = (((2*i-1)*I[2*i-2][1] % MM) * modpow(2*i, MM-2, MM) - modpow(two[2*i], MM-2, MM)) % MM;
    if (I[2*i][1] < 0) I[2*i][1] += MM;
    I[2*i][2] = ((2*i-1)*I[2*i-2][2] % MM) * modpow(2*i, MM-2, MM) % MM;
  }

  long a, b, c = 0;
  for (int i=0; i<N; i++) {
    a = (a + (A[i]*two[i] % MM)*I[i][0] % MM) % MM;
    b = (b + (A[i]*two[i] % MM)*I[i][1] % MM) % MM;
    c = (c + (A[i]*two[i] % MM)*I[i][2] % MM) % MM;
  }

  cout << a << b << c << endl;
}