new_contents: # http://codingbat.com/prob/p184853
  
  def big_diff(nums):
    max_num = nums[0]
    min_num = nums[0]
    
    for num in nums:
      max_num = max(num, max_num)
      min_num = min(num, min_num)
      
    return abs(max_num - min_num)
  
subject: Create big_diff.py