Q: Use a disfluent question or a proper question and find the answer to the question based on the given context or return None if an answer can't be found. A disfluent question is a question that has some interruptions in it while framing. A proper question is the correct form of the question without any disfluency.
proper question: How many companies were listed on the WSE on April 2009? 
 disfluent question: How many companies were listed on the PZPR no WSE on April 2009? 
 context: Warsaw's first stock exchange was established in 1817 and continued trading until World War II. It was re-established in April 1991, following the end of the post-war communist control of the country and the reintroduction of a free-market economy. Today, the Warsaw Stock Exchange (WSE) is, according to many indicators, the largest market in the region, with 374 companies listed and total capitalization of 162 584 mln EUR as of 31 August 2009. From 1991 until 2000, the stock exchange was, ironically, located in the building previously used as the headquarters of the Polish United Workers' Party (PZPR).
A:
None