In this task, you're given a context, further information available on a particular linked term from the statement, and an answer term. Your job is to generate a question that can use the information provided to obtain the given answer. You should use the information on both context and link information to create the question. Note that the answer to the question should be exactly the given answer, and if the answer is none, the answer to the question shouldn't be obtainable from the context or linked information.
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Question: Context: y headed by the Saltigue (the Serer priestly class) Link Information: none Answer: none

Answer: How many leaders run the priestly class?


Question: Context: Sia performed "Chandelier" on The Ellen DeGeneres Show on 19 May 2014, Link Information: The Ellen DeGeneres Show (often shortened to Ellen and stylized in all lowercase) is an American television variety comedy talk show hosted by Ellen DeGeneres. Debuting on September 8, 2003 Answer: 11

Answer: How long had the show in which Sia performed "Chandelier" in 2014 been on the air?


Question: Context: Working as the Graffiti Research Lab, Roth and Powderly developed open source tools for graffiti writers and activists, such as LED Throwies and L.A.S.E.R. Tag. Link Information:  LED throwies were invented in 2006 by the artists Evan Roth and James Powderly, the founder of Graffiti Research Lab at Eyebeam Atelier open lab New York City.  Answer: LED throwies

Answer:
Which of the open source tools for graffiti writers and activists that Powderly developed came first?