user: Question: What is the highest attendance at a game played by St. Johnstone?
Columns: ['Team', 'Stadium', 'Capacity', 'Highest', 'Lowest', 'Average']
Types: ['text', 'text', 'real', 'real', 'real', 'real']
Sample row: ['Dundee', 'Dens Park', 11856.0, 6192.0, 3146.0, 4264.0]
SQL:

assistant: SELECT "Highest" FROM "Table" WHERE "Team" = 'St. Johnstone';