#include <bits/stdc++.h>
using namespace std;

void fast_io() {
	ios_base::sync_with_stdio(false);
	cin.tie(nullptr);
}

int main() {
	fast_io();
	string s;
	cin >> s;
	long long ans = 0;
	vector<long long> cnt(26, 0);
	for (char c : s) {
		for (int i = 0; i < 26; i++) {
			if (c != 'A' + i) {
				ans += cnt[i] * (cnt[i] - 1) / 2;
			}
		}
		cnt[c - 'A']++;
	}
	cout << ans << endl;
}