user: Question: What is the largest Against with an Opposing Teams of Wales?
Columns: ['Opposing Teams', 'Against', 'Date', 'Venue', 'Status']
Types: ['text', 'real', 'text', 'text', 'text']
Sample row: ['Scotland', 12.0, '04/02/1989', 'Twickenham , London', 'Five Nations']
SQL:

assistant: SELECT MAX("Against") FROM "Table" WHERE "Opposing Teams" = 'Wales';