user: Question: How many assists were in the K-League competition, which has more than 20 total Gs, the Pohang Steelers team, and Chunnam Dragons as the opponent?
Columns: ['Name', 'Date', 'Goals', 'Assists', 'Team', 'Venue', 'Opponent', 'Competition', 'Total Gs', 'Total As']
Types: ['text', 'text', 'real', 'real', 'text', 'text', 'text', 'text', 'real', 'real']
Sample row: ['Choi Sang-Kuk', '1988-11-12', 27.0, 20.0, 'POSCO Atoms', 'Dongdaemun', 'Yukong Elephants', 'K-League', 32.0, 22.0]
SQL:

assistant: SELECT SUM("Assists") FROM "Table" WHERE "Competition" = 'K-League' AND "Total Gs" > 20.0 AND "Team" = 'Pohang Steelers' AND "Opponent" = 'Chunnam Dragons';