def get_count_coprime_number_count(prime_1: int, prime_2: int) -> int:
    """
    get_count_coprime_number_count returns the number of coprime numbers
    between prime_1 and prime_2

    Args:
        prime_1 (int): prime number
        prime_2 (int): prime number

    Returns:
        int: number of coprimes in the given range
    """
    return (prime_1 - 1) * (prime_2 - 1)