#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;
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;
}
const int M = 998244353, N = 1e6 + 10;
signed main()
{
    ios::sync_with_stdio(false);
    cin.tie(0);
    cout << setprecision(15) << fixed;
    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<i64, 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];
        sa[i] += s[i - 1][yi[a[i - 1]]];
        sa[i] %= M;
    }
    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 f1 = 0, f2 = 0, dp1 = 0, dp2 = 0, s1, s2;
            i128 res;
            f2 = s[n][j] - s[mp[i].back()][j];
            for (int z = mp[i].size() - 2; z >= 0; z--)
            {
                dp1 = (dp2 + (s[mp[i][z + 1]][j] - s[mp[i][z]][j]) * f2);
                f1 = ((s[n][j] - s[mp[i][z]][j]) + f2);
                i64 id = mp[i][z] - 1;
                if (id == 1)
                    continue;
                res = id * (id - 1) / 2;
                s1 = s[id][j], s2 = s[id][i];
                res = (res - sa[id] - s1 * s2 - (s1 + s2) * (id - s1 - s2)) * dp1;
                ans = (ans + res) % M;
                f2=f1,dp2=dp1;
            }
        }
    }
    cout << (int)ans << endl;
    return 0;
}