#include <bits/stdc++.h>
#define mod 998244353
using namespace std;

const int N = 1e6 + 10;
using ll = long long ;

int f[5][62][62], cnt[62], sum, val;

void add(int& a, int b) { a += b; if (a >= mod) a -= mod; }
int calc(int n) { return (ll)n * (n - 1) / 2 % mod; }
int query(int a, int b) { return ((ll)calc(sum - cnt[a] - cnt[b]) + calc(cnt[a]) + calc(cnt[b]) - val + mod) % mod; }

int id(char ch) {
	if (islower(ch)) return ch - 'a';
	else if (isupper(ch)) return 26 + (ch - 'A');
	else return 52 + (ch - '0');
}

void solve() {
	string s;
	cin >> s;
	
	sum = s.size();
	for (auto v : s) cnt[id(v)]++;
	
	for (int i = 0; i < 62; i++) {
		add(val, calc(cnt[i]));
		for (int j = 0; j < 62; j++) if (i != j) {
			f[0][i][j] = 1;
		}
	}
	
	int sz = s.size(), ans = 0;
	for (int i = sz - 1; i >= 0; i--) {
		int c = id(s[i]); 
		sum--; cnt[c]--;
		val = (val - cnt[c] + mod) % mod;
		for (int j = 0; j < 62; j++) if (c != j) {
			add(f[1][j][c], f[0][j][c]);
			add(f[3][j][c], f[2][c][j]);
			add(f[2][j][c], f[1][c][j]);
			add(ans, (ll)f[3][c][j] * query(c, j) % mod);
		}
	}
	cout << ans << '\n';
}

signed main() {
	ios::sync_with_stdio(false), cin.tie(0), cout.tie(0);
	solve();
	return 0;
}