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_39 (floors INTEGER, name VARCHAR, year VARCHAR)
### Question:
Name of 900 north michigan, and a Year smaller than 1989 involves what lowest floors?
### Answer:
SELECT MIN(floors) FROM table_name_39 WHERE name = "900 north michigan" AND year < 1989