#include <iostream>
using namespace std;
const int x= 2e3 + 5;
int n,T;
string s,t;
bool check(char a,char b){
	if (a == 'A' && b == 'T')	return 1;
	if (a == 'T' && b == 'A')	return 1;
	if (a == 'C' && b == 'G')	return 1;
	if (a == 'G' && b == 'C')	return 1;
	return 0;
}

long long calc(string s){
	string t = s;
	for (int i=0;i<s.size();i++)
		t[i] = s[n-1-i];
	long long ans = 0;
	for (int i=0;i<s.size();i++){
		if (s[i]!='A'&&s[i]!='T'&&s[i]!='C'&&s[i]!='G')	return 0;
		if (check(s[i],t[i]))	ans += i+1;
	}
	return ans;
}

int main(){
	cin >> T;
	while (T--){
		cin >> n;
		cin >> s;
		printf("%lld\n",calc(s));
	}
	return 0;
}