Terry, a lawyer, agrees with Chris, the client, to a $17,500 evergreen retainer. At the end of the first month, Terry invoices Chris for $1,000 dollars and takes $1,000 from the retainer. At the end of the second month, Terry invoices Chris for $5,000 dollars and takes $5,000 from the retainer. It is three days before the end of the third month, and Chris is in compliance with the retainer agreement. How much money is left in the retainer?