user: Question: How many parties were first elected in 1805?
Columns: ['District', 'Incumbent', 'Party', 'First elected', 'Result', 'Candidates']
Types: ['text', 'text', 'text', 'text', 'text', 'text']
Sample row: ['Virginia 2', 'James Stephenson', 'Federalist', '1809', 'Retired Federalist hold', 'John Baker (F) 56.5% Daniel Morgan (DR) 43.5%']
SQL:

assistant: SELECT COUNT("Party") FROM "Table" WHERE "First elected" = '1805';