In this task, you're given a statement, further information available on a particular linked term from the statement, and a question. Your job is to generate the answer to the question by using the information provided. If there is no clear answer obtainable, output 'none'.

Context: In 1874, Gill joined the expedition to Mauritius Link Information: Three years later he went to Ascension Island Question: Was the location Gill joined an expedition to in 1874 discovered before or after where he went three years later?
Answer: before