input: def is_prime(num):
      """Check if the given number is a prime number.
      >>> is_prime(2)
      True
      >>> is_prime(4)
      False
      >>> is_prime(7)
      True
      """
      # Iterate from 2 to the square root of the number
      for i in range(2, int(num ** 0.5) + 1):
          if num % i == 0:
              return False
      return True
output:     if num <= 1:
          return False