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

using ll = long long;

int main() {
    string S;
    cin >> S;
    int N(S.size());
    ll ans(0);
    vector P(26, 0LL);
    for(int i = 0; i < N; i++) {
        P[S[i]-'A']++;
        for(int j = 0; j < 26; j++) {
            if(j == S[i]-'A') continue;
            ans += (ll)P[j] * (ll)(P[j] - 1) / 2LL;
        }
    }
    cout << ans << endl;
    return 0;
}