At what age can you drop out of high school in South Korea?

Excuse me, I was wondering if you could clarify something for me regarding education in South Korea. Specifically, I'm curious to know, at what age is it permissible for an individual to drop out of high school in that country? Is there a legal age limit or are there any specific regulations that govern this decision? I'm interested in understanding the educational system in South Korea and how it differs from other countries in this regard. Thank you for your time and assistance.