#include <bits/stdc++.h>

using namespace std;
using ll = long long;

int main(){

    string S;
    cin >> S;
    ll N=S.size(), ans=0;

    vector<vector<ll>> cnt(N+1, vector<ll>(26));

    for (int i=1; i<=N; i++){
        cnt[i][S[i-1]-'A']++;
        for (int j=0; j<26; j++) cnt[i][j] += cnt[i-1][j];
    }

    for (int i=2; i<=N-1; i++){
        ans += cnt[i-1][S[i-1]-'A'] * (N-i-(cnt[N][S[i-1]-'A']-cnt[i][S[i-1]-'A']));
    }

    cout << ans << endl;

    return 0;
}