#include <bits/stdc++.h>
using namespace std;
using LL = long long;
constexpr int mod = 998244353;

void solve() {
	
	string s;
	cin >> s;

	int n = s.size();
	s = " " + s;

	auto get = [&] (char c) {
		if (c >= 'a' && c <= 'z') return c - 'a';
		else if (c >= 'A' && c <= 'Z') return c - 'A' + 26;
		else return c - '0' + 52;
	};

	vector<int> t(n + 1);
	for (int i = 1 ; i <= n ; ++i) {
		t[i] = get(s[i]);
	}

	constexpr int M = 62;
	vector<int> cnt(M) , sum(n + 1);
	vector<vector<int>> pos(M);
	vector<vector<int>> Pre(n + 1 , vector<int>(M));
	vector<vector<int>> lst(n + 1 , vector<int>(M));
	for (int i = 1 ; i <= n ; ++i) {
		for (int j = 0 ; j < M ; ++j) {
			Pre[i][j] = Pre[i - 1][j];
			lst[i][j] = lst[i - 1][j];
		}
		
		Pre[i][t[i]] += 1;
		pos[t[i]].emplace_back(i);

		int a1 = 1LL * cnt[t[i]] * (cnt[t[i]] - 1) / 2 % mod;
		cnt[t[i]] += 1;
		int a2 = 1LL * cnt[t[i]] * (cnt[t[i]] - 1) / 2 % mod;
		sum[i] = (1LL * sum[i - 1] + 1LL * a2 - 1LL * a1) % mod;
		lst[i][t[i]] = (1LL * lst[i][t[i]] + 1LL * a2 - 1LL * a1) % mod;
	}

	LL ans = 0;
	for (int i = 0 ; i < M ; ++i) {
		
		if (pos[i].empty()) continue;
		int m1 = pos[i].size() , k1 = m1 - 1;
		vector<int> dp(m1);
		int cnt_1_0 = 0;

		for (int j = 0 ; j < M ; ++j) {

			if (i == j || pos[j].empty() || pos[j].back() < pos[i][0]) continue;
			int cnt_0_0 = 0 , cnt_0_1 = 0;
			int m2 = pos[j].size() , k2 = m2 - 1;

			while (k1 >= 0  || k2 >= 0) {
				if (k1 >= 0 && k2 >= 0) {
					if (pos[i][k1] > pos[j][k2]) {
						cnt_1_0 += cnt_0_0;
						if (cnt_1_0 >= mod) cnt_1_0 -= mod;
						dp[k1] = cnt_0_1;
						k1 --;
					} else {
						cnt_0_0 += 1 , cnt_0_1 += cnt_1_0;
						if (cnt_0_1 >= mod) cnt_0_1 -= mod;
						k2 --;
					}
				} else if (k1 >= 0) {
					cnt_1_0 += cnt_0_0;
					if (cnt_1_0 >= mod) cnt_1_0 -= mod;
					dp[k1] = cnt_0_1;
					k1 --;
				} else {
					break;
				}
			}
			
			for (int k = 0 ; k < m1 ; ++k) {
				int p = pos[i][k];
				int a = ((p - 1 - Pre[p - 1][i]) % mod - Pre[p - 1][j]) % mod;
				LL a1 = 1LL * (1LL * a * (a - 1) / 2 - 1LL * sum[p - 1] + 1LL * lst[p - 1][i] + 1LL * lst[p - 1][j]) * dp[k] % mod;
				ans += a1;
				if (ans >= mod) ans -= mod;
				dp[k] = 0;
			}
			cnt_1_0 = 0 , k1 = m1 - 1;
			
		}
	}

	cout << ans << "\n";
}

int main() {

	ios::sync_with_stdio(false);
	cin.tie(nullptr);

	int t = 1;
	while (t--) {
		solve();
	}

	return 0;

}