Given the task definition, example input & output, solve the new input case.
Given a context passage, generate a question from the passage such that its answer is shortest continous span from the passage.
Example: In 1582 the united provinces invited francis, duke of anjou to lead them; but after a failed attempt to take antwerp in 1583, the duke left the netherlands again. after the assassination of william of orange (10 july 1584), both henry iii of france and elizabeth i of england declined the offer of sovereignty. however, the latter agreed to turn the united provinces into a protectorate of england (treaty of nonsuch, 1585), and sent the earl of leicester as governor-general. this was unsuccessful and in 1588 the provinces became a confederacy. the union of utrecht is regarded as the foundation of the republic of the seven united provinces, which was not recognized by the spanish empire until the peace of westphalia in 1648.
Output: In what year did francis, duke of anjou leave the netherlands?
The generated question is perfect. Because the question is based on second sentence of the input passage and its answer is 1583.

New input case for you: A volcanic eruption in Iceland has sent ash across northern Europe. Airlines have stopped or changed the flights across the Atlantic Ocean, leaving hundreds of passengers stuck in airports. Grimsvotn is one of the largest and most active volcanoes in Europe. What makes Grimsvotn different is that it lies under a huge glacier of ice up to 12 metres thick. The hot volcano heats up the ice above it, which then forms a layer of water between glacier and the volcano, keeping it stable. As the water flows out from under the glacier, the pressure lifts. The lava from the volcano then comes up to the surface. This is exactly what is happening today. Now airlines have to make changes to their flights so as not to fly through the clouds of volcanic ash. According to KLM, one of Europe's biggest airlines, airplanes cannot go under the cloud or over it. Going through the cloud can result in ash getting stuck in the airplane's engines, causing damage to the plane. The eruption has also caused problems for animals in Iceland. The volcano left ash and sharp, glass-like rocks all over the countryside. Farmers are keeping their animals inside to stop them eating ash-covered grass or the sharp objects.
Output:
how many passengers were forced to stay in the airport?