human
Considering the provided database schema and associated query, produce SQL code to retrieve the answer to the query. 
###Database Schema: Rank, Group, Athlete, Nationality, Result
###Question: What is the average rank for Group A athlete Yanina Karolchyk, and a result higher than 18?
gpt
SELECT AVG Rank FROM table WHERE Group = a AND Athlete = yanina karolchyk AND Result > 18