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_19089486_1 (clubs_involved INTEGER, leagues_entering_this_round VARCHAR, round VARCHAR)
### Question:
Name the least clubs involved for leagues being none for semi finals
### Answer:
SELECT MIN(clubs_involved) FROM table_19089486_1 WHERE leagues_entering_this_round = "none" AND round = "Semi finals"