#include <bits/stdc++.h>
#include<atcoder/all>
#define rep(i,n) for(int i=0;i<n;i++)
using namespace std;
using namespace atcoder;
#define all(a) a.begin(),a.end()
typedef long long ll;
typedef pair<ll,int> P;
typedef vector<ll> vi;
constexpr ll inf=1ll<<61;
constexpr ll mod=998244353;
typedef modint998244353 mi;
vector<ll>G[26];
int main(){
    string s;cin>>s;
    ll ans=0;
    int n=s.size();
    rep(i,n){
        G[s[i]-'A'].push_back(i);
    }
    rep(i,26){
        for(ll j=0;j<G[i].size();j++){
            ans+=j*(n-G[i][j]-1);
        }
        ll d=G[i].size();
        if(d>2)ans-=d*(d-1)*(d-2)/6;
    }
    cout<<ans<<endl;
}