What is the lowest rank of Gatwick Airport? 
CREATE TABLE table_18118221_1 (rank INTEGER, railway_station VARCHAR)
SELECT MIN(rank) FROM table_18118221_1 WHERE railway_station = "Gatwick Airport"
<s>[INST] Write mssql query to answer the following question given the database schema. Schema: CREATE TABLE table_18118221_1 (rank INTEGER, railway_station VARCHAR) Question: What is the lowest rank of Gatwick Airport?  [/INST] SELECT MIN(rank) FROM table_18118221_1 WHERE railway_station = "Gatwick Airport" </s>