In this task, you are given a question and a context passage. You have to answer the question based on the given passage.

Ex Input:
The expansion of what further cemented Houston's emergence as a powerhouse commercial city?, Context: By 1860, Houston had emerged as a commercial and railroad hub for the export of cotton. Railroad spurs from the Texas inland converged in Houston, where they met rail lines to the ports of Galveston and Beaumont. During the American Civil War, Houston served as a headquarters for General John Bankhead Magruder, who used the city as an organization point for the Battle of Galveston. After the Civil War, Houston businessmen initiated efforts to widen the city's extensive system of bayous so the city could accept more commerce between downtown and the nearby port of Galveston. By 1890, Houston was the railroad center of Texas.

Ex Output:
bayous


Ex Input:
Which of these Greeks knows more about physics: Joseph Sifakis or John Iliopoulos?, Context: As of 2007, Greece had the eighth highest percentage of tertiary enrollment in the world (with the percentages for female students being higher than for male) while Greeks of the Diaspora are equally active in the field of education. Hundreds of thousands of Greek students attend western universities every year while the faculty lists of leading Western universities contain a striking number of Greek names. Notable modern Greek scientists of modern times include Dimitrios Galanos, Georgios Papanikolaou (inventor of the Pap test), Nicholas Negroponte, Constantin Carathéodory, Manolis Andronikos, Michael Dertouzos, John Argyris, Panagiotis Kondylis, John Iliopoulos (2007 Dirac Prize for his contributions on the physics of the charm quark, a major contribution to the birth of the Standard Model, the modern theory of Elementary Particles), Joseph Sifakis (2007 Turing Award, the "Nobel Prize" of Computer Science), Christos Papadimitriou (2002 Knuth Prize, 2012 Gödel Prize), Mihalis Yannakakis (2005 Knuth Prize) and Dimitri Nanopoulos.

Ex Output:
John Iliopoulos


Ex Input:
A monument in London that commemorates the husband of Queen Victoria is?, Context: The Monument in the City of London provides views of the surrounding area while commemorating the Great Fire of London, which originated nearby. Marble Arch and Wellington Arch, at the north and south ends of Park Lane respectively, have royal connections, as do the Albert Memorial and Royal Albert Hall in Kensington. Nelson's Column is a nationally recognised monument in Trafalgar Square, one of the focal points of central London. Older buildings are mainly brick built, most commonly the yellow London stock brick or a warm orange-red variety, often decorated with carvings and white plaster mouldings.

Ex Output:

Albert Memorial