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 Customers_cards (customer_id VARCHAR)
  ### Question:
  What is the customer id with most number of cards, and how many does he have?
  ### Answer:
  SELECT customer_id, COUNT(*) FROM Customers_cards GROUP BY customer_id ORDER BY COUNT(*) DESC LIMIT 1