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

### Instruction:
What is the maximum ITV1 weekly ranking?

### Inputs:
table_name: table, columns: ['#', 'Airdate', 'No. of couples', 'First couple', 'Second couple', 'Third couple', 'Fourth couple', 'Viewers (millions)', 'ITV1 weekly ranking']

### Response:
SELECT MAX ITV1 weekly ranking FROM table