text: 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 table_28138035_20 (mens_singles VARCHAR, mens_doubles VARCHAR)
  ### Question:
  How many players are there for mens singles when chen qi ma lin played mens doubles?
  ### Answer:
  SELECT COUNT(mens_singles) FROM table_28138035_20 WHERE mens_doubles = "Chen Qi Ma Lin"