#include<bits/stdc++.h>
#include <iostream>
using namespace std;
#include<atcoder/all>
using namespace atcoder;
using ll = long long;
using mint = modint998244353;
const int MAX = 505050;
mint fac[MAX],facinv[MAX];
void init(){
	fac[0] = fac[1] = 1;
	facinv[0] = facinv[1] = 1;
	for(int i = 2;i<MAX;i++){
		fac[i] = fac[i-1] * i;
		facinv[i] = fac[i].inv();
	}
}
mint biom(int n,int k){
	if(n<k)return 0;
	if(n<0||k<0)return 0;
	return fac[n]*facinv[k]*facinv[n-k];
}

mint routesum(int x,int y){
	return biom(x+y,x);
}

int N;
vector<int> a;

void solve(){
	mint ans = 0;
	for(int i = 0;i<N;i++){
		mint coef = biom(N+i-1,i) - biom(N+i-1,i-1);
		ans += mint(a[N-i-1])*(coef);
	}
	cout<< ans.val() << endl;
}

signed main(){
	cin.tie(nullptr);
	ios::sync_with_stdio(false);
	init();
	cin >> N;
	a = vector<int>(N);
	for(int i = 0;i<N;i++){
		cin >> a[i];
	}
	solve();
}