#include <bits/stdc++.h>
using namespace std;
using ll = long long;
#define rep(i, s, e) for (int i = (int)(s); i < (int)(e); ++i)

int main() {
	cin.tie(nullptr);
	ios_base::sync_with_stdio(false);
	
	string S;
	cin >> S;
	
	vector<ll> cnt(26);
	ll ans = 0;
	for (char c : S) {
		rep(i, 0, 26) if (i != c - 'A') {
			ans += cnt[i]*(cnt[i] - 1) / 2;
		}
		++cnt[c - 'A'];
	}
	cout << ans << '\n';
}