#include <iostream>
#include <string>
#include <vector>
#include <algorithm>
#include <utility>
#include <map>
#include <set>
#include <queue>
#include <iomanip>
#include <cmath>
#include <atcoder/all>
using namespace std;
using namespace atcoder;
typedef long long ll;
#define rep(i,n) for (int i = 0; i < int(n);i++)

int main(){
	string s;
	cin >> s;
	vector<ll> cnt(26);
	int n = s.size();
	ll ans = 0;
	for (int i = 0; i < n;i++){
		int c = int(s[i]-'A');
		for (int j = 0; j < 26;j++){
			if (c == j) continue;
			ans += ll(cnt[j])*ll(cnt[j]-1)/2;
		}
		cnt[c]++;
	}
	cout << ans << endl;

	
	return 0;
}