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

const int N = 1e5 + 10;
int n, l;
long long s;
char a[N];

int main(){
	cin >> n;
	for(int i = 1; i <= n; i++){
		cin >> l;
		for(int j = 1; j <= l; j++){
			cin >> a[j];
			if(!(a[j] == 'A' || a[j] == 'T' || a[j] == 'C' || a[j] == 'G')){
				cout << "0" << endl;
				break;
			}
			if(j == l){
				for(int k = 1; k <= l; k++){
					if((a[k] == 'A' && a[l - k + 1] == 'T') || (a[k] == 'T' && a[l - k + 1] == 'A') || (a[k] == 'C' && a[l - k + 1] == 'G') || (a[k] == 'G' && a[l - k + 1] == 'C')){
						s += k;
					}
				}
				cout << s << endl;
				s = 0;
			}
		}
		
	}
	return 0;
}