#include <iostream>
#include <vector>
#include <algorithm>
#include <cmath>
#include <atcoder/all>
using namespace std;
using namespace atcoder;
using ll = long long;
using mint = modint998244353;
using vi = vector<int>;
using vvi = vector<vi>;
using vvvi = vector<vvi>;
using vll = vector<ll>;
using vvll = vector<vll>;
using vvvll = vector<vvll>;
using vmi = vector<mint>;
using vvmi = vector<vmi>;
using vvvmi = vector<vvmi>;
#define all(a) (a).begin(), (a).end()
#define rep2(i, m, n) for (int i = (m); i < (n); ++i)
#define rep(i, n) rep2(i, 0, n)
#define drep2(i, m, n) for (int i = (m)-1; i >= (n); --i)
#define drep(i, n) drep2(i, n, 0)


int main(){

    string s; cin >> s;
    vvi pos(26);
    rep(i, s.length()){
        int c = s[i] - 'A';
        pos[c].push_back(i);
    }
    ll len = s.length();
    ll ans = 0;
    rep2(i, 1, len-1){
        int c = s[i] - 'A';
        ll cnt = upper_bound(all(pos[c]), i) - begin(pos[c]);
        ll size = pos[c].size();
        ans += (cnt-1)*(len-(ll)i-1 - (size-cnt));
    }cout << ans << endl;
    return 0;
}