1881_dont_try_to_count.py

def dont_try_to_count():
    n, m = map(int, input().split())
    x = input()
    s = input()

    """Approach 1"""
    # operations = 0
    # while len(x) <= n * m:
    #     if s in x:
    #         return operations
    #     x *= 2
    #     operations += 1
    # else:
    #     if s in x:
    #         return operations
    #     return -1

    """
    Approach 2
        the worst case is n = 1 and m = 25
        then x has to repeat 5 times (2^5) to reach a length > s
        -> so just repeat the loop 5 times for every case
    """
    for i in range(6):
        if s in x:
            return i
        x *= 2
    return -1


t = int(input())
for _ in range(t):
    print(dont_try_to_count())