#include<bits/stdc++.h>
using namespace std;
using ll = long long;
#define rep(i,m,n) for(int i=m; i<int(n); ++i)
#define repll(i,m,n) for(ll i=m; i<ll(n); ++i)
#define all(a) (a).begin(), (a).end()
#define rall(a) (a).rbegin(), (a).rend()
#define fi first
#define se second

template<typename T> bool chmin(T& a, T b){ if(a > b){a = b; return true;} return false; }
template<typename T> bool chmax(T& a, T b){ if(a < b){a = b; return true;} return false; }

template<typename T> T gcd(T a, T b){ return a % b ? gcd(b, a % b) : b; }
template<typename T> T lcm(T a, T b){ return a / gcd(a, b) * b; }

int main(){
    ios::sync_with_stdio(false);
    cin.tie(nullptr);

    string s;
    cin >> s;

    int n = s.size();
    s = '?' + s;

    vector cnt(n+1, vector<int>(26, 0));
    rep(i, 1, n+1){
        rep(j, 0, 26){
            cnt[i][j] = cnt[i-1][j];
            if(s[i] == char('A' + j)) ++cnt[i][j];
        }
    }

    /*
    rep(j, 0, 26){
        rep(i, 0, n+1) cout << cnt[i][j];
        cout << endl;
    }
    */

    ll ans = 0LL;
    rep(i, 1, n+1){
        int j = s[i] - 'A';
        rep(k, 0, 26){
            if(k == j) continue;
            ans += 1LL*(cnt[i-1][k])*(cnt[i-1][k] - 1LL)/2LL;
        }
    }
    cout << ans << endl;

    return 0;
}