Subject to Landlord's payment or reimbursement obligations under Paragraph 4(b) hereof with respect to the Tenant Improvement Allowance, Tenant shall promptly pay all costs and expenses arising out of the performance of Tenant's Work (including the costs of permits) and shall furnish Landlord with evidence of payment on request. Tenant shall provide Landlord with ten (10) days' prior written notice before commencing any Tenant's Work. On completion of Tenant's Work (assuming Landlord has complied with its payment or reimbursement obligations under Paragraph 4(b) hereof), Tenant shall deliver to Landlord a release and unconditional lien waiver executed by each contractor, subcontractor and materialman involved in the performance of Tenant's Work. If any lien is filed against the Property or against Tenant's leasehold interest, Tenant shall obtain, within ten (10) days after the filing, the release or discharge of that lien. If Tenant fails to do so, Landlord shall have the right (but not the obligation) to obtain the release or discharge of the lien and Tenant shall, within fifteen (15) days after written demand by Landlord (accompanied by reasonable documentation of the items claimed), reimburse Landlord for all costs, including (but not limited to) reasonable attorneys' fees, incurred by Landlord in obtaining the release or discharge of such lien, together with interest from the date of demand at the interest rate set forth in Section 3.2 of the Lease.