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

Example Input: What type of equipment is used with liquid oxygen but not other methods of oxygen storage?, Context: Oxygen storage methods include high pressure oxygen tanks, cryogenics and chemical compounds. For reasons of economy, oxygen is often transported in bulk as a liquid in specially insulated tankers, since one liter of liquefied oxygen is equivalent to 840 liters of gaseous oxygen at atmospheric pressure and 20 °C (68 °F). Such tankers are used to refill bulk liquid oxygen storage containers, which stand outside hospitals and other institutions with a need for large volumes of pure oxygen gas. Liquid oxygen is passed through heat exchangers, which convert the cryogenic liquid into gas before it enters the building. Oxygen is also stored and shipped in smaller cylinders containing the compressed gas; a form that is useful in certain portable medical applications and oxy-fuel welding and cutting.
Example Output: heat exchangers

Example Input: Which of the following is not the title of a leader: president, emperor, or Chihuahua?, Context: Under threat from the conservative forces, Governor Terrazas was deposed, and the state legislature proclaimed martial law in the state in April 1864 and established Jesús José Casavantes as the new governor. In response, José María Patoni decided to march to Chihuahua with presidential support. Meanwhile, Maximilian von Habsburg, a younger brother of the Emperor of Austria, was proclaimed Emperor Maximilian I of Mexico on April 10, 1864 with the backing of Napoleon III and a group of Mexican conservatives. Before President Benito Juárez was forced to flee, Congress granted him an emergency extension of his presidency, which would go into effect in 1865 when his term expired, and last until 1867. At the same time, the state liberals and conservatives compromised to allow the popular Ángel Trías take the governorship; by this time the French forces had taken control over the central portions of the country and were making preparations to invade the northern states.
Example Output: Chihuahua

Example Input: What had been done to the twentieth century homes?, Context: The area is also known for its early twentieth century homes, many of which have been restored in recent decades. The area includes many California Bungalow and American Craftsman style homes, Spanish Colonial Revival Style architecture, Mediterranean Revival Style architecture, Mission Revival Style architecture, and many Storybook houses designed by Fresno architects, Hilliard, Taylor & Wheeler. The residential architecture of the Tower District contrasts with the newer areas of tract homes urban sprawl in north and east areas of Fresno.
Example Output:
restored