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_73 (weight_class__kg_ INTEGER, venue VARCHAR)
### Question:
What is the lowest weight class (kg) that has sofia, bulgaria as the venue?
### Answer:
SELECT MIN(weight_class__kg_) FROM table_name_73 WHERE venue = "sofia, bulgaria"