using namespace std;

//O(n·s)

int main() {
	ios::sync_with_stdio(false);
	cin.tie(nullptr);
	cout.tie(nullptr);
	int n;
	cin>>n;
	for(int i=0;i<n;i++){
		int s;
		long long stable=0;
		cin>>s;
		string k1;
		cin>>k1;
		string k2=k1;
		reverse(k2.begin(),k2.end());
		for(int j=0;j<s;j++){
			if((k1[j]=='C'&&k2[j]=='G')||(k1[j]=='G'&&k2[j]=='C')||
			   (k1[j]=='A'&&k2[j]=='T')||(k1[j]=='T'&&k2[j]=='A')){
				stable+=(j+1);
			}
			if(k1[j]!='C'&&k1[j]!='G'&&k1[j]!='T'&&k1[j]!='A'){
				stable=0;
				break;
			}
		}
		cout<<stable<<"\n";
	}
}