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'.
One example: Context: During Operation Market Garden, the attempt to seize a bridgehead across the Rhine in the Netherlands, the 704th dropped supplies to allied troops near Nijmegen. Link Information: Operation Market Garden was a failed World War II military operation fought in the Netherlands from 17 to 25 September 1944. Question: When did the operation during which the 704th dropped supplies to allied troops near Nijmegen begin?
Solution is here: from 17 to 25 September 1944
Explanation: The context describes the 704th's actions during Operation Market Garden, and the answer specifies when the operation happened.

Now, solve this: Context: He made his debut for Sunderland on 21 September 1929 against Arsenal in a 1–0 loss at Roker Park. Link Information: In 1929 the old wooden grandstand was demolished and replaced by a new Main Stand, which was designed by Archibald Leitch, whose influence, the criss-cross lattice work, can still be seen at Ibrox (Rangers), Home Park (Plymouth Argyle) and Goodison Park (Everton). Fragments of the iconic lattice work would later be used to separate parts of the car park at the Stadium of Light. The work on the new Main Stand nearly bankrupted the club. By this time the official capacity of Roker Park was 60,000 Question: What was the seating capacity at Roker Park in 1929?
Solution:

Show your work and conclude with the exact phrasing "Therefore, the final answer is [answer]." where [answer] is just the final number or expression that solves the problem.
user
Answer: 60,000