Below is an instruction that describes a task. Write a response that appropriately completes the request.

### Instruction:
What is the latest task number for which Cathy is head of household?

### Inputs:
table_name: table, columns: ['Task No.', 'Date given', 'Head of Household', 'Hand Grenade User', 'Hand Grenade Recipient']

### Response:
SELECT MAX Task No. FROM table WHERE Head of Household = cathy