user: Question: For all events with index F10, what is the sum of the overall rankings?
Columns: ['Index', 'Name', 'Talent Segment', 'Acting Segment', 'Overall Ranking', 'Status']
Types: ['text', 'text', 'text', 'text', 'real', 'text']
Sample row: ['F6', '林佩琪 Lin Peiqi', 'Tap Dancing', 'Kiasu Student', 4.0, 'Eliminated']
SQL:

assistant: SELECT SUM("Overall Ranking") FROM "Table" WHERE "Index" = 'F10';