#include<bits/stdc++.h>
using namespace std;
using ll = unsigned long long;

int main(){
    string S;cin >> S;
    map<char,vector<int>>mp;
    int N = S.size();
    for(int i = 0;i < N;i++){
        mp[S[i]].push_back(i);
    }
    int ans = 0;
    for(auto &p:mp){
        //最初の二文字をpから取り出す
        auto &pos = p.second;
        char c = p.first;
        int s = pos.size();
        if(s<2)continue;
        //cout << s << endl;
        int cnt2 = 0;
        for(int i = 1;i < (int)pos.size();i++){
            //前半の文字の選び方はi通り
            //後半がpos[i]にあるとき
            int cnt = 0;
            for(int j = pos[i]+1;j < N;j++){
                if(S[j]!=c)cnt++;
            }
            cnt2+=cnt*i;
        }
        ans+=cnt2;
    }
    cout << ans << endl;
}