Margo owns one of the 10 condominium units in her building, which is insured to value by the condo association subject to a $25,000 deductible. Margo's condominium unit-owners policy, Insurance Services Office, Inc., form HO 6 (2011 edition), includes the standard $1,000 loss assessment limits. The building sustains $40,000 in damage by a covered peril, and the association assesses each unit owner with its proportionate share of the loss that insurance does not cover. 

Margo's out-of-pocket (uninsured) costs in this situation are?