#include <bits/stdc++.h>
using namespace std;
const int N=500005,Mod=998244353;
#define ll long long
struct Node{
	int x;
	ll y;
}a[N];
int s[N],top;
ll cross(Node a,Node b,Node c){
	ll x=b.x-a.x,xx=c.x-a.x;
	ll y=b.y-a.y,yy=c.y-a.y;
	return 1ll*y*xx-1ll*x*yy;
}
inline int qpow(int a,int b){
	int ans=1;
	while (b){
		if (b&1) ans=1ll*ans*a%Mod;
		a=1ll*a*a%Mod,b>>=1;
	}
	return ans;
}
int main() {
	int n;scanf ("%d",&n);
	for (int i=1;i<=n;i++){
		a[i].x=i;
		scanf ("%lld",&a[i].y);
	}
	s[top=1]=1;
	for (int i=2;i<=n;i++){
		while (top>1&&cross(a[s[top-1]],a[s[top]],a[i])<=0) top--;
		s[++top]=i;
	}
	int ans=0,lst=1;
	for (int i=1;i<=n;i++){
		while (lst<=top&&a[s[lst]].x<i) lst++;
		if (a[s[lst]].x==i) ans+=a[i].y;
		else ans+=1ll*(1ll*(a[s[lst]].x-i)*a[s[lst-1]].y+1ll*(i-a[s[lst-1]].x)*a[s[lst]].y)%Mod*qpow(a[s[lst]].x-a[s[lst-1]].x,Mod-2)%Mod;
	}
	printf ("%d",1ll*ans*qpow(n,Mod-2)%Mod);
	return 0;
}