#include "bits/stdc++.h"
#define rep(i, a, n) for (auto i = a; i <= (n); ++i)
#define revrep(i, a, n) for (auto i = n; i >= (a); --i)
#define all(a) a.begin(), a.end()
#define sz(a) (int)(a).size()
template<class T> bool chmin(T &a, T b) { if (b < a) { a = b; return 1; } else return 0; }
template<class T> bool chmax(T &a, T b) { if (b > a) { a = b; return 1; } else return 0; }
using namespace std;

template<class A> string to_string(const A &v) {
	bool first = 1;
	string res = "{";
	for (const auto &x: v) {
		if (!first) res += ", ";
		first = 0;
		res += to_string(x);
	}
	res += ")";
	return res;
}

void debug_out() { cerr << endl; }
template<class H, class... T> void debug_out(const H&h, const T&... t) {
	cerr << " " << to_string(h);
	debug_out(t...);
}
#define debug(...) cerr << "[" << #__VA_ARGS__ << "]:", debug_out(__VA_ARGS__)

using ll = long long;
using pii = pair<int, int>;
using vi = vector<int>;
using vvi = vector<int>;

template<class T> struct Point {
	using P = Point;
	using type = T;
	static constexpr T eps = 1e-9;
	static constexpr bool isInt = is_integral_v<T>;
	
	static int sgn(T x) { return (x > eps) - (x < -eps); }
	static int cmp(T x, T y) { return sgn(x - y); }

	T x, y;

	P operator +(P a) const { return P{x + a.x, y + a.y}; }
	P operator -(P a) const { return P{x - a.x, y - a.y}; }
	P operator *(T a) const { return P{x * a, y * a}; }
	P operator /(T a) const { return P{x / a, y / a}; }
	bool operator ==(P a) { return cmp(x, a.x) == 0 && cmp(y, a.y) == 0; }

	T len2() const { return x * x + y * y; }
	T len() const { return sqrt(x * x + y * y); }

	P unit() const { 
		if (isInt) return *this;
		else return len() <= eps ? P{} : *this / len();
	}

	T dot(P b) const { return x * b.x + y * b.y; }
	T cross(P b) const { return x * b.y - y * b.x; }

	P rotate(T theta) const {
		P a{cos(theta), sin(theta)};
		return P{x * a.x - y * a.y, x * a.y + y * a.x};
	}

	T project_len(P a, P b) const {
		if (isInt) return (*this - a).dot(b - a);
		else if (a == b) return 0;
		else return (*this - a).dot(b - a) / (b - a).len();
	}

	T dis_to_line(P a, P b) const {
		if (isInt) return (*this - a).cross(b - a);
		else if (a == b) return 0;
		else return (*this - a).cross(b - a) / (b - a).len();
	}
	
	T dis_to_seg(P a, P b) const {
		if (project_len(a, b) <= eps) return (*this - a).len();
		if (project_len(b, a) <= eps) return (*this - b).len();
		return fabs(dis_to_line(a, b));
	}

	friend string to_string(P p) { return "(" + to_string(p.x) + ", " + to_string(p.y) + ")"; }
};

template<const int &mod> struct Z {
	int x;
	Z(ll a = 0): x (a % mod) { if (x < 0) x += mod; }
	explicit operator int() const { return x; }

	Z& operator +=(Z b) { x += b.x; if (x >= mod) x -= mod; return *this; }
	Z& operator -=(Z b) { x -= b.x; if (x < 0) x += mod; return *this; }
	Z& operator *=(Z b) { x = 1ll * x * b.x % mod; return *this; }
	friend Z operator +(Z a, Z b) { return a += b; }
	friend Z operator -(Z a, Z b) { return a -= b; }
	friend Z operator *(Z a, Z b) { return a *= b; }

	Z pow(ll k) const {
		Z res = 1, a = *this;
		for (; k; k >>= 1, a = a * a) if (k & 1) res = res * a;
		return res;
	}
	Z& operator /=(Z b) {
		assert(b.x != 0);
		*this = *this * b.pow(mod - 2);
		return *this;
	}
	friend Z operator /(Z a, Z b) { return a /= b; }

	friend string to_string(Z a) { return to_string(a.x); }
};

const int mod = 998244353;
using Mint = Z<mod>;

int main() {
	ios::sync_with_stdio(0); cin.tie(0);

	using T = ll;
	using P = Point<T>;
	
	int n; cin >> n;
	vector<ll> as(n);
	for (auto &x: as) cin >> x;
	vector<P> ps(n);
	rep(i, 0, n - 1) ps[i] = {i, as[i]};
	vector<P> hull;
	rep(i, 0, n - 1) {
		P a = ps[i];
		while (sz(hull) >= 2 && (a - hull.end()[-1]).cross(hull.end()[-1] - hull.end()[-2]) <= 0) {
			hull.pop_back();
		}
		hull.push_back(a);
	}
	vi nums;
	for (auto &p: hull) nums.push_back(p.x);

	Mint ans = 0;
	rep(i, 0, n - 1) {
		int pos = lower_bound(all(nums), i) - nums.begin();
		int r = nums[pos];
		if (r == i) {
			ans += Mint{as[i]};
		} else {
			int l = nums[pos - 1];
			Mint val = Mint{as[l]} * (r - i) + Mint{as[r]} * (i - l);
			val /= Mint{r - l};
			ans += val; 
		}
	}
	ans /= n;
	printf("%d\n", (int) ans);
	return 0;
}