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 song (f_id VARCHAR, formats VARCHAR, resolution INTEGER); CREATE TABLE files (f_id VARCHAR, formats VARCHAR, resolution INTEGER)
### Question:
What are the ids of songs that are available in either mp4 format or have resolution above 720?
### Answer:
SELECT f_id FROM files WHERE formats = "mp4" UNION SELECT f_id FROM song WHERE resolution > 720