user: Question: What is the smallest silver from Vietnam?
Columns: ['Rank', 'Nation', 'Gold', 'Silver', 'Bronze', 'Total']
Types: ['real', 'text', 'real', 'real', 'real', 'real']
Sample row: [1.0, 'Singapore', 11.0, 9.0, 6.0, 26.0]
SQL:

assistant: SELECT MIN("Silver") FROM "Table" WHERE "Nation" = 'Vietnam';