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

### Instruction:
What is the highest rank of a building erected in 1976 with fewer than 21 floors?

### Inputs:
table_name: table, columns: ['Rank', 'Name', 'Height ft / m', 'Floors', 'Year']

### Response:
SELECT MAX Rank FROM table WHERE Year = 1976 AND Floors < 21