def is_prime(num):
  """
  This function checks if a number is prime.
  """
  if num <= 1:
    return False
  for i in range(2, int(num**0.5) + 1):
    if num % i == 0:
      return False
  return True

# Loop through 3-digit numbers starting with 5
for num in range(500, 1000):
  # Check if prime and print if it is
  if is_prime(num):
    print(num)