#include<iostream>
#include<algorithm>
#include<string>
#include<cstring>
#include<cstdio>
using namespace std;
const int N = 3e6 + 10;
const int mod = 998244353;
int i, j, n, m, k, l, a[N * 4], tree[N * 4][11], root, num, r, d[N * 4], wz, f[N * 4][24], pos[N * 4], g[N * 2], qz[30], x, y, lg[N * 2 + 1];
long long ans;
string s;
inline void update(int x)
{
	for (int i = 1; i <= 23; ++i)
		f[x][i] = f[f[x][i - 1]][i - 1];
}
inline int up(int x, int y)
{
	if (!y) return x;
	for (int i = lg[y]; i >= 0; i = lg[y]) 
		x = f[x][i], y -= qz[i];
	return x;
}
inline void dfs1(int x, int y, int dep, int hh)
{
	for (int i = 0; i <= 10; ++i)
		if (tree[x][i])
		{
			if (x == 0)
			{
				if (i == 10) dfs1(tree[x][i], 1, dep + 1, i);
				else dfs1(tree[x][i], 0, dep + 1, i);
			}
			else dfs1(tree[x][i], y, dep + 1, i);
			g[x] += g[tree[x][i]]; g[x] %= mod;
		}
	if (x && hh != 10)
	{
		if (y)
		{
			int gs = dep / 2; gs *= 2;
			if (gs <= n)ans += 1ll * gs * g[x] % mod * g[x] % mod;
			ans %= mod;
		}
		else
		{
			int gs = dep / 2 + (dep % 2 != 0); gs = gs * 2 - 1;
			if (gs <= n)ans += 1ll * gs * g[x] % mod * g[x] % mod;
			ans %= mod;
		}
	}
}
int main()
{
	//freopen("1.in","r",stdin);
	ios::sync_with_stdio(false);
	cin.tie(0); cout.tie(0);
	for (int i = 1; i <= N * 2; i++)lg[i] = lg[i - 1] + (1 << lg[i - 1] == i);
	for (int i = 0; i <= N * 2; i++)lg[i]--;
	cin >> n >> s;
	a[0] = 0; a[++a[0]] = 10;
	for (i = 1; i <= n; ++i)
	{
		a[++a[0]] = s[i - 1] - '0';
		a[++a[0]] = 10;
	}
	for (i = 1; i <= n; ++i)
	{
		a[++a[0]] = s[i - 1] - '0';
		a[++a[0]] = 10;
	}
	qz[0] = 1;
	for (i = 1; i <= 23; ++i) qz[i] = qz[i - 1] * 2;
	root = 0; num = 0;
	for (i = 1, l = 1, r = 0; i <= 2 * n; ++i)
	{
		wz = root;
		if (!tree[wz][a[i]]) {
			tree[wz][a[i]] = ++num;
			f[num][0] = wz;
			update(num);
		}
		wz = tree[root][a[i]];
		if (i > r)
		{
			k = 1;
			g[wz]++;
			g[f[wz][0]]--;
		}
		else
		{
			if (d[l + r - i] <= r - i + 1)
			{
				k = d[l + r - i];
				x = pos[l + r - i];
				g[x]++;
				g[f[wz][0]]--;
				wz = x;
			}
			else
			{
				k = r - i + 1;
				y = d[l + r - i] - (r - i + 1);
				x = pos[l + r - i];
				x = up(x, y);
				g[x]++;
				g[f[wz][0]]--;
				wz = x;
			}
		}

		while (1 <= i - k && i + k <= 4 * n + 2 && a[i - k] == a[i + k]) {
			if (!tree[wz][a[i + k]])
			{
				tree[wz][a[i + k]] = ++num;
				f[num][0] = wz;
				update(num);
			}
			g[wz]--;
			g[tree[wz][a[i + k]]]++;
			wz = tree[wz][a[i + k]];
			k++;
		}
		pos[i] = wz;
		d[i] = k--;
		if (i + k > r) {
			l = i - k;
			r = i + k;
		}
	}
	for (i = 2 * n + 1, l = 1, r = 0; i <= 4 * n + 1; ++i)
	{
		wz = root;
		if (!tree[wz][a[i]]) {
			tree[wz][a[i]] = ++num;
			f[num][0] = wz;
			update(num);
		}
		wz = tree[root][a[i]];
		if (i > r)
		{
			k = 1;
			g[wz]++;
			g[f[wz][0]]--;
		}
		else
		{
			if (d[l + r - i] <= r - i + 1)
			{
				k = d[l + r - i];
				x = pos[l + r - i];
				g[x]++;
				g[f[wz][0]]--;
				wz = x;
			}
			else
			{
				k = r - i + 1;
				y = d[l + r - i] - (r - i + 1);
				x = pos[l + r - i];
				x = up(x, y);
				g[x]++;
				g[f[wz][0]]--;
				wz = x;
			}
		}

		while (1 <= i - k && i + k <= 4 * n + 2 && a[i - k] == a[i + k]) {
			if (!tree[wz][a[i + k]])
			{
				tree[wz][a[i + k]] = ++num;
				f[num][0] = wz;
				update(num);
			}
			g[wz]--;
			g[tree[wz][a[i + k]]]++;
			wz = tree[wz][a[i + k]];
			k++;
		}
		pos[i] = wz;
		d[i] = k--;
		int len = 0;
		if (i - d[i] + 1 <= 2 * n) len = i - (2 * n);
		else len = d[i];
		x = pos[i]; y = d[i] - len;
		x = up(x, y);
		g[x]--;
		if (i + k > r) {
			l = i - k;
			r = i + k;
		}
	}
	dfs1(root, 0, 0, 10);
	ans = (ans % mod + mod) % mod;
	cout << ans << endl;
}