/**
* written by Binoy Barman .
**/
#include<bits/stdc++.h>
using namespace std;
#define nl '\n'
#define all(v) v.begin(), v.end()
#define Too_Many_Jobs int tts, tc = 1; cin >> tts; hell: while(tts--)
#define Dark_Lord_Binoy ios_base::sync_with_stdio(false); cin.tie(NULL);
#ifdef LOCAL
#include "unravel.hpp"
#else
#define dbg(...) 42
#endif
#define ll long long
template<typename T> T nPr(T n, T r) {
T sum = 1;
for(T i = 1; i <= r; i++) {
sum = sum * (n - r + i);
}
return sum;
}
int32_t main() {
Dark_Lord_Binoy
#ifdef LOCAL
freopen("input.txt", "r", stdin);
freopen("output.txt", "w", stdout);
#endif
Too_Many_Jobs {
int n;
cin >> n;
string s;
cin >> s;
vector<ll> a(26, 0);
for(auto i : s) {
a[i - 'a']++;
}
ll ans = 0;
for (int i = 0; i < 26; i++) {
if(a[i] > 1) {
ans += nPr(a[i], 2LL);
}
}
cout << ans << nl;
}
return 0;
}