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_7 (began_operation INTEGER, length__km_ VARCHAR, stations VARCHAR)
### Question:
When is the earliest began operation with a length of sultan ismail and over 27 stations?
### Answer:
SELECT MIN(began_operation) FROM table_name_7 WHERE length__km_ = "sultan ismail" AND stations > 27