new_contents: """Solution to Project Euler Problem 3
  https://projecteuler.net/problem=3
  """
  
  from math import floor, sqrt
  
  NUMBER = 600851475143
  
  
  def compute(number=NUMBER):
      """Find the largest prime factor of `number`."""
  
      factors = list()
  
      for test_prime in range(3, floor(sqrt(number)), 2):
          if number % test_prime == 0:
              factors.append(test_prime)
              number /= test_prime
              if number == 1:
                  break
  
      return factors[-1]
  
subject: Complete Problem 3