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_16 (assets__us INTEGER, company VARCHAR, revenues__us$_billion_ VARCHAR)
### Question:
What are the smallest assets with a Company of piraeus bank, and a Revenue (US$ billion) smaller than 3.9?
### Answer:
SELECT MIN(assets__us) AS $_billion_ FROM table_name_16 WHERE company = "piraeus bank" AND revenues__us$_billion_ < 3.9