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

### Instruction:
What is the longest length of mandatory secondary school?

### Inputs:
table_name: table, columns: ['Canton', 'Years of Kindergarten', 'Years of Kindergarten provided', 'Years of Kindergarten legally required', 'Length of Primary School', 'Length of mandatory Secondary School', 'Separate Secondary Schools?', 'Cooperative Secondary Schools?', 'Integrated Secondary Schools?']

### Response:
SELECT MAX Length of mandatory Secondary School FROM table