Joyce is self-employed and uses the calendar year and the accrual method of accounting. She reports the following activities for December:

	Received $10,000 from clients for services to be performed next year
	Received $30,000 for services performed in December
	Reports $15,000 in accounts receivable for work performed in December
	Received $2,000 for services performed in November

What amount must Joyce include in gross income for December?