#include <bits/stdc++.h>
using namespace std;
#ifdef LOCAL
  #include "settings/debug.cpp"
  #define _GLIBCXX_DEBUG
#else
  #define Debug(...) void(0)
#endif
using ll = long long;
#define rep(i, n) for (int i = 0; i < (n); ++i)

int main() {
  string s;
  cin >> s;
  vector idx(26, vector<int>(0));
  rep(i, s.size()) {
    idx[s[i] - 'A'].push_back(i);
  }
  ll ans = 0;
  rep(i, s.size()) {
    rep(j, 26) {
      if (s[i] == 'A' + j) continue;
      auto itr = lower_bound(idx[j].begin(), idx[j].end(), i);
      ll cnt = itr - idx[j].begin();
      ans += cnt * (cnt - 1) / 2;
    }
  }
  cout << ans << endl;
  return 0;
}