Dan and Maureen file a joint income tax return for 2018. They have two dependent children, ages 7 and 9. Together they earn wages of $830,000. They also receive taxable interest income of $8,000 and interest on City of Los Angeles bonds of $78,000. During 2018, they received a state income tax refund of $3,000 relating to their 2017 state income tax return on which they itemized deductions. Their expenses for the year consist of the following:

Home mortgage interest (on acquisition debt)

$19,000

Interest on credit cards

$2,000

Real property taxes

$8,300

Cash contributions

$75,000

State income taxes withheld

$48,000

Calculate Dan and Maureen's tentative minimum tax liability assuming an AMT exemption amount of $109,400, before any phase-outs. Show your calculations.