Timo is the sole owner of Jazz Inc., an S corporation. On October $31,2023,$ Timo executed an unsecured demand promissory note of $$15,000$ and transferred the note to Jazz $($Jazz could require Timo to pay it $$15,000$ on demand$).$ When Timo transferred the note to Jazz, his tax basis in his Jazz stock was zero. On January $31,2024,$ Timo paid the $$15,000$ to Jazz as required by the promissory note. For the taxable year ending December $31,2023,$ Jazz incurred a business loss of $$12,000.$ How much of the loss clears the stock and debt basis hurdles for deductibility?