from sys import stdin
input=stdin.readline
t=int(input())
for _ in range(t):
    n=int(input())
    s=input()
    if len(s.replace('A','').replace('T','').replace('G','').replace('C',''))!=0:
        print(0)
        continue
    s1=s[::-1]
    cnt=0
    for i in range(n):
        if (s[i]=='A' and s1[i]=='T') or (s[i]=='T' and s1[i]=='A') or (s[i]=='G' and s1[i]=='C') or (s[i]=='C' and s1[i]=='G'):
            cnt+=(i+1)
    print(cnt)