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

#define FAST ios_base::sync_with_stdio(false);cin.tie(NULL);
using ll = long long;

int main() {
  FAST;
  
  int tc = 1, ti;
  cin >> tc;

  for (ti = 1; ti <= tc; ++ti) {
    ll n, ans;
    string s;
    cin >> n >> s;

    map<char,ll> mp;
    for (char c : s) mp[c] += 1;

    ans = 0;
    for (auto [_, cnt] : mp) ans += cnt*(cnt-1);

    cout << ans << "\n";
  }

  return 0;
}