new_contents: from itertools import combinations as combs
  
  def find_counterfeit(coins):
      good, found = set(), set()
      for i,j in combs(range(len(coins)),2):
          if not balanced(coins[i],coins[j]): 
              found.add(i); found.add(j)
          else:
              good.add(i); good.add(j)            
      result = [x for x in found.difference(good)]
      return result[0] if result else None
  
subject: Create beta_found_the_counterfeit.py