#include <bits/stdc++.h>
using namespace std;
#define fi first
#define se second
#define Mp make_pair
#define pb push_back
#define SZ(a) (int(a.size()))

typedef long long ll;
typedef double db;
typedef std::pair<int, int> pii;
typedef std::vector<int> vi;
#define log(...) fprintf(stderr, __VA_ARGS__)
std::mt19937_64 gen(std::chrono::system_clock::now().time_since_epoch().count());
ll get(ll l, ll r) { std::uniform_int_distribution<ll> dist(l, r); return dist(gen); }

const int BASE = 10, MAXN = 10000100, P = 998244353;

int n, ans; string s;
struct PAM {
    int nxt[MAXN][BASE], fail[MAXN], cnt[MAXN], num[MAXN], len[MAXN], str[MAXN];
    ll size;
    int pre, suf, p, m, head, tail;
    int newnode(int x) {
        for (int i = 0; i < BASE; i++) nxt[p][i] = 0;
        cnt[p] = num[p] = 0, len[p] = x;
        return p++;
    }
    void init() {
        p = 0;
        newnode(0), newnode(-1);
        pre = suf = size = m = 0, head = 5, tail = head - 1;
        memset(str, -1, sizeof(str));
        fail[0] = 1;
    }
    int get_fail(int x) {
        while (tail - len[x] - 1 < 0 ||
                str[tail - len[x] - 1] != str[tail]) x = fail[x];
        return x;
    }
    void add(int c, int p) {
        int cur, now;
        m++;
        str[++tail] = c, cur = get_fail(suf);
        if (!nxt[cur][c]) {
            now = newnode(len[cur] + 2);
            fail[now] = nxt[get_fail(fail[cur])][c];
            nxt[cur][c] = now;
            num[now] = num[fail[now]] + 1;
        }
        suf = nxt[cur][c], size += num[suf];
        if(p > n) cnt[suf]++;
    }
    void count() {
        for (int i = p - 1; i >= 0; i--) {
            cnt[fail[i]] += cnt[i];
            if(len[i] <= n)
                ans = (ans + 1ll * cnt[i] * cnt[i] % P * len[i]) % P;
        }
    }
} T;

signed main() {
    atexit([](){cerr << "time: " << (db)clock()/CLOCKS_PER_SEC << "s\n";});
    ios::sync_with_stdio(false), cin.tie(0), cout.tie(0);
    cin >> n >> s;
    T.init();
    for(int i = 0; i < 2 * n; i++) {
        // cout << i << endl;
        T.add(s[i % n] - '0', i + 1);
    }
    T.count();
    cout << ans << '\n';
    return 0;
}