#include <bits/stdc++.h>
using namespace std;
typedef long long ll;

int main() {
    string S;
    cin >> S;

    ll n = S.length();
    map<char, set<ll>> mp;
    for (ll i = 0; i < n; ++i) {
        mp[S[i]].insert(i);
    }

    ll ans = 0;
    for (ll i = 0; i < n; ++i) {
        mp[S[i]].erase(i);
        if (!mp[S[i]].size()) continue;

        // j より後ろにある個数
        ll nokori = mp[S[i]].size() - 1;
        for (ll j : mp[S[i]]) {
            ll tmp = n - j - 1 - nokori;
            ans += tmp, nokori--;
        }
    }

    cout << ans << endl;
}