#include<bits/stdc++.h>
using namespace std;
#define N 500050
typedef long long ll;
const int mod=998244353;
int n,inv[N];
ll a[N];
struct Point{
	ll x,y;
	Point(ll _x=0,ll _y=0):x(_x),y(_y){}
	friend Point operator - (const Point &a,const Point &b){
		return Point(a.x-b.x,a.y-b.y);
	}
	friend ll operator % (const Point &a,const Point &b){
		return a.x*b.y-a.y*b.x;
	}
};
inline bool Left(Point a,Point b){
	return b%a>0;
}
void init(int n){
	inv[1]=1;
	for(int i=2;i<=n;++i){
		inv[i]=1LL*inv[mod%i]*(mod-mod/i)%mod;
	}
}
int main(){
	ios::sync_with_stdio(false);
	cin.tie(0);
	cin>>n;
	init(n);
	for(int i=1;i<=n;++i){
		cin>>a[i];
	}
	static int st[N],top;
	for(int i=1;i<=n;++i){
		while(top>1&&!Left(Point(st[top],a[st[top]])-Point(st[top-1],a[st[top-1]]),Point(i,a[i])-Point(st[top-1],a[st[top-1]])))--top;
		st[++top]=i;
	}
	int ans=a[n];
	for(int k=1;k<top;++k){
		for(int i=st[k];i<st[k+1];++i){
			ans=(ans+a[st[k]]+1LL*(a[st[k+1]]-a[st[k]])%mod*(i-st[k])%mod*inv[st[k+1]-st[k]])%mod;
		}
	}
	ans=(ans+mod)%mod;
	cout<<1LL*ans*inv[n]%mod<<'\n';
	return 0;
}