user: Question: Tell me the lowest round for Total Combat 15
Columns: ['Res.', 'Record', 'Opponent', 'Method', 'Event', 'Round', 'Time', 'Location']
Types: ['text', 'text', 'text', 'text', 'text', 'real', 'text', 'text']
Sample row: ['Loss', '14-11', 'Evgeny Erokhin', 'TKO (knees)', 'Pankration: Mayor Cup 2013', 3.0, '4:40', 'Khabarovsk , Russia']
SQL:

assistant: SELECT MIN("Round") FROM "Table" WHERE "Event" = 'Total Combat 15';