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

#define int long long

int32_t main () {
  cin.tie(0)->sync_with_stdio(0);
  int t = 1;
  cin >> t;
  while (t--) {
      int n, ans = 0;
      cin >> n;
      string s;
      cin >> s;
      int a[26]{};
      for (auto u : s) a[u-'a']++;
      for (int i = 0; i < 26; i++) {
          ans += ((a[i]*a[i])-a[i]);
      }
      cout << ans << "\n";
  }
}