Detailed Instructions: 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'.
Q: Context: He commanded the submarine HMS Alderney from 1946, the submarine HMS Aeneas from 1950 and then the aircraft carrier in the 1960s. Link Information: none Question: Which submarine did Ian McIntosh command for the longest amount of years?
A:
Answer: none