Rosita Flores, who is single and age 56, had financial information for 2018 as follows:

• Taxable income (prior to the standard deduction), $540,000.
• Positive AMT adjustments, $60,000.
• AMT preferences, $30,000.
• Negative AMT adjustments, $10,000.
• State income taxes, $8,000.
• Real estate taxes, $7,500.
• Home mortgage (80% for qualified housing), $25,000.
• Investment interest, $2,500.
• Contributions (cash), $7,500.

Compute Rositas AMT base for 2018.