Below is an context that describes a sql query, paired with an question that provides further information. Write an answer that appropriately completes the request.  # noqa: E501
### Context:
CREATE TABLE matches (winner_name VARCHAR, tourney_name VARCHAR, winner_hand VARCHAR)
### Question:
How many different winners both participated in the WTA Championships and were left handed?
### Answer:
SELECT COUNT(DISTINCT winner_name) FROM matches WHERE tourney_name = 'WTA Championships' AND winner_hand = 'L'