user: Question: What is the highest round in the wec 25 match in las vegas, nevada, united states?
Columns: ['Res.', 'Record', 'Opponent', 'Method', 'Event', 'Round', 'Location']
Types: ['text', 'text', 'text', 'text', 'text', 'real', 'text']
Sample row: ['Loss', '10-6', 'Tiawan Howard', 'Decision (split)', 'CES MMA VI: Nowhere To Hide', 3.0, 'Lincoln, Rhode Island , United States']
SQL:

assistant: SELECT MAX("Round") FROM "Table" WHERE "Location" = 'las vegas, nevada, united states' AND "Event" = 'wec 25';