You will be given a definition of a task first, then some input of the task.
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: Ogasawara served in combat during the First Sino-Japanese War Link Information: at the Battle of the Yalu River. Question: How long after the start of the First Sino-Japanese War did the Battle of the Yalu River take place?
Output:
Answer: 54