human
Considering the provided database schema and associated query, produce SQL code to retrieve the answer to the query. 
###Database Schema: Name, Year, Landfall, NHC Advisory Number, V(mph), R(miles), Saffir-Simpson Category
###Question: What was the highest SaffirSimpson with an NHC advisory of 18?
gpt
SELECT MAX Saffir-Simpson Category FROM table WHERE NHC Advisory Number = 18