user: Question: What country has Signed type moving from Porto?
Columns: ['Name', 'Country', 'Type', 'Moving from', 'Transfer window', 'Ends', 'Transfer fee', 'Source']
Types: ['text', 'text', 'text', 'text', 'text', 'real', 'text', 'text']
Sample row: ['Codina', 'ESP', 'Promoted', 'Youth system', 'Summer', 2010.0, 'Youth system', 'Realmadrid']
SQL:

assistant: SELECT "Country" FROM "Table" WHERE "Type" = 'Signed' AND "Moving from" = 'Porto';