def Z_algorithm(s):
    
    n = len(s)
    if n == 0:
        return []

    z = [0]*n
    j = 0
    for i in range(1,n):
        z[i] = 0 if j + z[j] <= i else min(j+z[j]-i,z[i-j])
        while i + z[i] < n and s[z[i]] == s[i+z[i]]:
            z[i] += 1
            if j + z[j] < i + z[i]:
                j = i
    z[0] = n
    return z


def solve():

    n = int(input())

    S = input()

    Z = Z_algorithm(S)

    ans = 0

    for i in range(1,n):
        z = Z[i]


        if z == n-i:
            if i+1 <= n-i:
                ans += 1
        else:
            if S[z] < S[i+z] or z >= i:
                ans += 1

    print(ans)

t = int(input())
for _ in range(t):
    solve()