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

### Instruction:
What is the high goal against associated with 18 wins, a Goal Difference of 43, and under 6 draws?

### Inputs:
table_name: table, columns: ['Position', 'Club', 'Played', 'Wins', 'Draws', 'Losses', 'Goals for', 'Goals against', 'Points', 'Goal Difference']

### Response:
SELECT MAX Goals against FROM table WHERE Wins = 18 AND Goal Difference = 43 AND Draws < 6