#include <bits/stdc++.h>

using namespace std;

#define ll long long
#define rep(i, a, n) for (int i = (int)(a); i < (int)(n); i++)
#define rrep(i, n, a) for (int i = (int)(n); i >= (int)(a); i--)

void solve(){
    string s; cin >> s;
    ll ans = 0;
    vector<int> app(26,0);
    int l = s.size();
    rep(i,0,l){
        int ind = (int)s[i]-(int)'A';
        app[ind]++;
        rep(j,0,26){
            if(j != ind && app[j] >= 2){
                ans += app[j]*(app[j]-1)/2;
            }
        }
    }

    cout << ans;
}

int main(){
    ios::sync_with_stdio(false);
    cin.tie(0);
    solve();

    return 0;
}