user: Question: What is the latest task number for which Cathy is head of household?
Columns: ['Task No.', 'Date given', 'Head of Household', 'Hand Grenade User', 'Hand Grenade Recipient']
Types: ['real', 'text', 'text', 'text', 'text']
Sample row: [1.0, 'December 10, 2009 (Day 68)', 'Paul Jake', 'Carol', 'Hermes']
SQL:

assistant: SELECT MAX("Task No.") FROM "Table" WHERE "Head of Household" = 'Cathy';