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_name_56 (round_2 VARCHAR, round_4 VARCHAR, round_3 VARCHAR)
### Question:
What is Round 2 when Round 4 is Double and Round 3 is Single?
### Answer:
SELECT round_2 FROM table_name_56 WHERE round_4 = "double" AND round_3 = "single"