def read_numbers_from_file(file_path): #cau a
    numbers = []
    with open(file_path, 'r') as file:
        line = file.readline().strip()
        numbers_str = line.split()
        for num_str in numbers_str:
            numbers.append(float(num_str))
    return numbers

def find_negative_numbers(numbers): #cau b
    negative_numbers = []
    for num in numbers:
        if num < 0:
            negative_numbers.append(num)
    return negative_numbers

def calculate_average_positive(numbers): #cau c
    positive_numbers = [num for num in numbers if num > 0]
    if not positive_numbers:
        return None
    average = sum(positive_numbers) / len(positive_numbers)
    return average

def is_prime(num): #cau d
    if num <= 1:
        return False
    for i in range(2, int(num**0.5) + 1):
        if num % i == 0:
            return False
    return True

def find_prime_numbers(numbers):
    return [num for num in numbers if is_prime(num)]

def calculate_average(numbers): #cau e
    total = sum(numbers)
    average = total / len(numbers)
    return average