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

#define ll long long int
#define vecint vector<int>
#define vecchar vector<char>
#define max_ele(v) *max_element(v.begin(), v.end())
#define min_ele(v) *min_element(v.begin(), v.end())
#define sort(v) sort(v.begin(), v.end())
#define rev_sort(v) sort((v).begin(), (v).end(), greater<>())
#define Reverse(v) reverse(v.begin(), v.end())
#define pb push_back
#define ppb pop_back()
#define pf push_front
#define coutall(v)     \
    for (auto &it : v) \
    cout << it << " "
#define coutnewline(v) \
    for (auto &it : v) \
    cout << it << '\n'
#define cinall(v)      \
    for (auto &it : v) \
    cin >> it
#define yes cout << "YES\n"
#define no cout << "NO\n"

void solve()
{
    int n, same = 0;
    cin >> n;
    cin.ignore();
    string ch;
    getline(cin, ch);
    for (int i = 0; i < n - 1; i++)
    {
        for (int j = i + 1; j < n; j++)
        {
            if (ch[i] == ch[j])
                same++;
        }
    }
    cout << 2 * same<<endl;
}

int main()
{
    int tests;
    cin >> tests;
    while (tests-- > 0)
    {
        solve();
    }
    return 0;
}