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

int main(){
    string S;
    cin >> S;
    int l = S.length();
    ll ans=0;
    map<char,int> ser;
    for(int i=0;i<l;i++){
        int a = 'A';
        for(int j=0;j<26;j++){
            char c = (char)(a+j);
            if(S[i] == c){
                continue;
            }
            if(ser[c] >= 2){
                int su = ser[c];
                ll pl = su*(su-1)/2;
                ans += pl;
            }
        }
        ser[S[i]]++;
    }
    cout << ans << endl;
}