C corp. is an accrual basis taxpayer. In $2023,$ C corp.$$s income statement reflects a warranty expense of $$100,000$ for products sold in $2023.$ Of that, $$80,000$ reflects costs that were actually incurred by the company in $2023,$ and the remaining $$20,000$ is reflected as an increase of $$20,000$ to the allowance for existing warranty contracts on the company$$s balance sheet $($based on an estimate that they will need to provide warranty services worth $$20,000$ in a future year for product sold in $2023).$ What amount of warranty expense may C corp. deduct in $2023?$