using namespace std;

#include <iostream>
#include <vector>
#include <utility>
#include <algorithm>

int main(){
    string S;
    cin >> S;
    int S_len = S.length();

    vector<vector<int>> chars_indexes(26, vector<int>(0));

    for (int i = 0; i < S_len; i++){
        chars_indexes.at(S.at(i)-65).push_back(i);
    }

    long long ans = 0;

    for (auto indexes : chars_indexes){
        if (indexes.size() < 2){
            continue;
        }
        long long last_number = S_len - indexes.back() - 1;
        int count = 0;
        for (int i = indexes.size()-2; i >= 0; i--){
            count ++;
            ans += last_number;
            last_number += S_len - indexes.at(i) - 1 - count;
        }
    }

    cout << ans << endl;
}