#include <bits/stdc++.h>
#include <atcoder/all>
using namespace std;
using namespace atcoder;
using ll = long long;
using ld = long double;
using mint = modint998244353;

int main() {
  string S; cin >> S;
  map<char, vector<int>> mp;
  for (int i = 0; i < S.size(); i++) {
    mp[S[i]].push_back(i);
  }
  ll ans = 0;
  for (int i = 0; i < S.size(); i++) {
    if (mp[S[i]].size() >= 2) {
      int pos1 = lower_bound(mp[S[i]].begin(), mp[S[i]].end(), i) - mp[S[i]].begin();
      if (pos1 < mp[S[i]].size() - 1) {
        for (int j = pos1 + 1; j < mp[S[i]].size(); j++) {
          int siz = max(0, (int)mp[S[i]].size() - j - 1);
          ans += S.size() - mp[S[i]][j] - 1 - siz;
          //cout << S[i] << ' ' << S.size() - mp[S[i]][pos1 + 1] - 1 - siz << endl;
        }
      }
    }
  }
  cout << ans << endl;
  return 0;
}