Question: On which stock exchange does the makers of Panadol night have a primary listing?
Related documents: [0]  [DOC] The company has a primary listing on the London Stock Exchange and is a constituent of the FTSE 100 Index. As of August 2016 it had a market capitalisation of £81 billion (around $107 billion), the fourth largest on the London Stock Exchange. It has a secondary listing on the New York Stock Exchange. [END] 
[1]  [DOC] Panadol night is a GlaxoSmithKline painkiller intended for use at night. It consists of 500 milligrams of paracetamol, 25 milligrams of diphenhydramine hydrochloride (a sedating antihistamine) and other "non-hazardous ingredients" It is sold in Australia, Cyprus United Kingdom, Ireland, New Zealand and the Middle East. It became available as an over the counter medication in the UK in 1996. [END] 
Answer: 
the London Stock Exchange
the London Stock Exchange