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

template <class T> int sz(T&& a) { return int(size(forward<T>(a))); }

template <class T> using vc = vector<T>;
template <class T> using vvc = vector<vector<T>>;

using ll = int64_t;

template <int K, class S> struct eertree {
	struct N { /// start-hash
		int suf, anc, l, r;
		array<int, K> ch;
		int len() const { return r-l; }
	};
	vc<N> n;
	int c;
	S s;
	eertree(int alloc = 0) {
		if (alloc > 2) n.reserve(alloc);
		n.push_back({-1, -1, 1, 0, {}});
		n.push_back({0, -1, 0, 0, {}});
		reset();
	}
	void reset() {
		c = 1;
		s.clear();
	} /// end-hash

	int dist(int v) { /// start-hash
		return n[v].suf <= 0 ? -1 : n[v].len() - n[n[v].suf].len();
	} /// end-hash
	template <class A> int extend(A a) { /// start-hash
		int i = sz(s);
		s.push_back(a);
		auto works = [&](int v) -> bool {
			int l = i - n[v].len();
			return l > 0 && s[l-1] == s[i];
		};
		while (!works(c)) c = n[c].suf;
		if (!n[c].ch[s[i]]) {
			int d = n[c].suf;
			if (d != -1) while (!works(d)) d = n[d].suf;
			int e = (d == -1 ? 1 : n[d].ch[s[i]]);
			int f = n[c].ch[s[i]] = sz(n);
			n.push_back({e, e, i - n[c].len() - 1, i + 1, {}});
			if (dist(e) == dist(f)) n[f].anc = n[e].anc;
		}
		return c = n[c].ch[s[i]];
	} /// end-hash

	const N& operator [] (int i) const {
		return n[i];
	}
};

int main() {
	ios_base::sync_with_stdio(false), cin.tie(nullptr);

	int N;
	cin >> N;
	string S;
	cin >> S;

	eertree<10, vc<int>> et(2*N+10);
	for (int i = 0; i < N; i++) {
		int a = int(S[i] - '0');
		et.extend(a);
	}
	vc<int> locs(N);
	for (int i = 0; i < N; i++) {
		int a = int(S[i] - '0');
		locs[i] = et.extend(a);
	}

	int num_et = int(et.n.size());
	vc<int> dp(num_et);
	for (int v : locs) {
		dp[v]++;
	}

	constexpr int MOD = 998244353;
	auto add = [&](int& a, int b) -> void {
		a += b;
		if (a >= MOD) a -= MOD;
	};

	int ans = 0;
	for (int v = num_et-1; v >= 2; v--) {
		add(dp[et[v].suf], dp[v]);
		int len = et[v].len();
		if (len <= N) {
			int cur = int(ll(dp[v]) * dp[v] % MOD * len % MOD);
			add(ans, cur);
		}
	}
	cout << ans << '\n';

	return 0;
}