user: Question: What's the sum of swing to gain with a winning party 2007 of Conservative with a rank smaller than 5?
Columns: ['Rank', 'Constituency', 'Winning party 2007', 'Swing to gain', "PC's place 2007", 'Result']
Types: ['real', 'text', 'text', 'real', 'text', 'text']
Sample row: [1.0, 'Carmarthen West & South Pembrokeshire', 'Conservative', 0.44, '3rd', 'Conservative hold']
SQL:

assistant: SELECT SUM("Swing to gain") FROM "Table" WHERE "Winning party 2007" = 'Conservative' AND "Rank" < 5.0;