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

const int mod = 998244353;
string ts = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";

int ys(char x){
	if (x >= 'a' && x <= 'z') return x - 'a';
	if (x >= 'A' && x <= 'Z') return x - 'A' + 26;
	return x - '0' + 52;
}


void solve() {
	string s;
	cin >> s;
	int n = s.size();
	vector<int> pos[62];
	for (int i = 0;i < n;i ++)
		pos[ys(s[i])].push_back(i);
	int pre[n];
	int cnt[62] = {};
	pre[0] = 0;
	cnt[ys(s[0])] = 1;
	for (int i = 1;i < n;i ++){
		cnt[ys(s[i])] ++;
		pre[i] = (pre[i - 1] + (i + 1 - cnt[ys(s[i])])) % mod;
//		cout << i << " " << pre[i] << "\n";
	}
	int ans = 0;
	for (int i = 0;i < 62;i ++)
		for (int j = i + 1;j < 62;j ++){
			int ni = pos[i].size();
			int nj = pos[j].size();
			int p[ni + nj];
			int topi = 0,topj = 0,top = 0;
			while(topi < ni && topj < nj){
				if (pos[i][topi] < pos[j][topj]) p[top ++] = pos[i][topi ++];
				else p[top ++] = pos[j][topj ++];
			}
			while(topi < ni) p[top ++] = pos[i][topi ++];
			while(topj < nj) p[top ++] = pos[j][topj ++];
//			cout << ts[i] << " " << ts[j] << "\n";
//			for (int k = 0;k < top;k ++) cout << p[k] << " ";
//			cout << "\n";
			int dp[top] = {};
			int cnti = 0,cntj = 0;
			for (int k = top - 1;k >= 0;k --){
				if (s[p[k]] == ts[i]){
					dp[k] = cntj;
					cnti ++;
				}else{
					dp[k] = cnti;
					cntj ++;
				}
			}
			cnti = 0,cntj = 0;
			for (int k = top - 1;k >= 0;k --){
				if (s[p[k]] == ts[i]){
					cnti = (cnti + dp[k]) % mod;
					dp[k] = cntj;		
				}else{	
					cntj = (cntj + dp[k]) % mod;
					dp[k] = cnti;
				}
			}
			cnti = 0,cntj = 0;
			for (int k = top - 1;k >= 0;k --){
				if (s[p[k]] == ts[i]){
					cnti = (cnti + dp[k]) % mod;
					dp[k] = cntj;
				}else{
					cntj = (cntj + dp[k]) % mod;
					dp[k] = cnti;
				}
			}
			cnti = 0,cntj = 0;
			for (int k = 0;k < top;k ++){
				if (p[k] > 1) ans = (ans + dp[k] * ((pre[p[k] - 1] - cnti * (p[k] - cnti) - cntj * (p[k] - cntj) + cnti * cntj) % mod)) % mod;
				if (s[p[k]] == ts[i]) cnti ++;
				else cntj ++;
			}
//			cout << ts[i] << " " << ts[j] << " " << ans << "\n";
		}
	ans = (ans % mod + mod) % mod;
	cout << ans << "\n";
}

signed main() {
	ios::sync_with_stdio(false);
	cin.tie(0); cout.tie(0);
	int _ = 1;
//	cin >> _;
	while(_ --) solve();
	return 0;
}