As part of a prior 2018-2019 audit cycle, the IRS is issued a 2018 deficiency of $10,000, a penalty of $2,000 and interest of $100.  The IRS also issued a deficiency for 2019 of $20,000, a penalty of $5,000 and interest of $500.  The client said he paid $11,000 a few weeks ago without designating the category to which it applies.  How will the $11,000 payment be applied?