import sys
input = sys.stdin.readline

T=int(input())
for tests in range(T):
    N=int(input())
    S=input().strip()

    # Z algorithm
    # https://snuke.hatenablog.com/entry/2014/12/03/214243

    LEN=len(S)
    i=1
    j=0
    A=[0]*LEN
    A[0]=LEN

    while i<LEN:
        while i+j<LEN and S[j]==S[i+j]:
            j+=1
        A[i]=j
        
        if j==0:
            i+=1
            continue
        
        k=1
        while i+k<LEN and k+A[k]<j:
            A[i+k]=A[k]
            k+=1
        i+=k
        j-=k

    #print(A)

    ANS=0

    for i in range(1,N):
        L=i
        R=N-i
        
        a=A[i]

        if a==R:
            if L<a:
                ANS+=1
            continue
        if a==L:
            ANS+=1
            continue

        if S[a]<S[i+a]:
            ANS+=1

    print(ANS)