#pragma GCC optimize(3,"Ofast","inline")
#include <bits/stdc++.h>
#define dug(x) cerr << "死了吧小丑" << x << endl
using namespace std;
using i64 = long long;
using i128 = __int128;

std::istream& operator>>(std::istream& is, i128& n) { n = 0; std::string s; is >> s; for (auto c : s) { n = 10 * n + c - '0'; } return is; }
std::ostream& operator<<(std::ostream& os, i128 n) { if (n == 0) { return os << 0; }std::string s;while (n > 0) { s += '0' + n % 10;n /= 10; }std::reverse(s.begin(), s.end());return os << s; }
template <class T> bool chmax(T &a, T b)
{
    a > b ? (a = a) : (a = b);
    return a == b;
}
template <class T> bool chmin(T &a, T b)
{
    a > b ? (a = b) : (a = a);
    return a == b;
}

constexpr int M = 998244353;

void add(int &x, int y) {
    x += y;
    while (x >= M) x -= M;
    while (x < 0) x += M;
}

signed main() {
    ios::sync_with_stdio(false);
    cin.tie(0);
    int yi[128]{};
    vector<char> tm(62);
    for (int i = 0; i < 26; i++)
    {
        yi[i + 'A'] = i;
        tm[i] = i + 'A';
        yi[i + 'a'] = i + 26;
        tm[i + 26] = i + 'a';
    }
    for (int i = 0; i < 10; i++)
    {
        yi[i + '0'] = i + 52;
        tm[i + 52] = i + '0';
    }
    string a;
    cin >> a;
    int n = a.size();
    vector<array<int, 62>> s(n + 1);
    fill(s[0].begin(), s[0].end(), 0);
    vector<vector<int>> mp(62);
    for (int i = 1; i <= n; i++)
    {
        s[i] = s[i - 1];
        s[i][yi[a[i - 1]]]++;
        mp[yi[a[i - 1]]].push_back(i);
    }
    vector<int> sa(n + 1, 0);
    for (int i = 1; i <= n; i++)
    {
        sa[i] = sa[i - 1];
        add(sa[i], s[i - 1][yi[a[i - 1]]]);
    }
    i128 ans = 0;
    for (int i = 0; i < 62; i++)
    {
        if (mp[i].size() <= 1) continue;
        for (int j = 0; j < 62; j++)
        {
            if (i == j) continue;
            i64 f[2]{}, dp[2]{};
            i128 res{};
            f[1] = s[n][j] - s[mp[i].back()][j];
            for (int z = mp[i].size() - 2; z >= 0; z--)
            {
                dp[0] = 0;
                dp[0] += dp[1] + i128(s[mp[i][z + 1]][j] - s[mp[i][z]][j]) * f[1];
                f[0] = s[n][j] - s[mp[i][z]][j] + f[1];
                int id = mp[i][z] - 1;
                if (id == 1) continue;
                res = 1LL * id * (id - 1) / 2;
                int s1 = s[id][j], s2 = s[id][i];
                res -= sa[id];
                res -= 1LL * s1 * s2;
                res -= 1LL * (s1 + s2) * (id - s1 - s2);
                ans += res * dp[0];
                std::swap(f[0], f[1]), std::swap(dp[0], dp[1]);
            }
        }
        ans %= M;
    }

    if (ans < 0) {
        ans += M;
    }
    std::cout << ans << '\n';

    return 0;
}