In this task, you're given a question, along with a context passage which has extra information available on certain terms mentioned in it. Your job is to determine which sentence(s) from the passage can be used to search for further information needed to answer the question.

Ex Input:
Question: What were the main groups involved in the event that resulted in the sacking of Constantinople in 1204? Passage:Papal calls for renewed holy war at the end of the twelfth century inspired not only the disastrous Fourth Crusade that sacked Constantinople in 1204, but also a series of simultaneous "Northern Crusades" that are less fully covered in English-language popular history, but which were more successful in the long run. Before the crusades, the region of Livonia was a mixed outpost, a pagan society where merchants from the Hanseatic League encountered merchants of Novgorod, and where Germanic, Scandinavian, and Russian trade, culture, and cults all mingled. The specific ethnic groups that intermingled and traded with the Germans, Danish, Swedish, and Russians here included the Wends, who were merchants from Lübeck, the Estonians, the Karelians, the Kuronians, the Lettgallians, the Semgallians (sometimes known as the Letts), the Livonians and the Lithuanians. The Western merchants would trade silver, textiles, and other luxury goods for furs, beeswax, honey, leather, dried fish, and amber. Livonia had been an especially promising location in terms of resources, and Arnold of Lübeck, in his Chronicle of the Slavs wrote that the land was "abundant in many riches" and was "fertile in fields, plentiful in pastures, irrigated by rivers", and "also sufficiently rich in fish and forested with trees".


Ex Output:
Papal calls for renewed holy war at the end of the twelfth century inspired not only the disastrous Fourth Crusade that sacked Constantinople in 1204, but also a series of simultaneous "Northern Crusades" that are less fully covered in English-language popular history, but which were more successful in the long run


Ex Input:
Question: Who was the leader of Hungary during the Hungarian Revolution of 1848? Passage:The last meetings had revealed the rising antagonism with Britain and France, especially on Italian unification, the right to self-determination and the Eastern Question. The Alliance is conventionally taken to have become defunct with Alexander's death in 1825. France ultimately went her separate way after the July Revolution of 1830, leaving the core of Russia, Austria and Prussia as Central-Eastern European block which once again congregated to suppress the Revolutions of 1848. The Austro-Russian alliance finally broke up in the Crimean War: though Russia had helped to completely destroy the Hungarian Revolution of 1848, Austria did not take any action to support her ally, declared herself neutral and even occupied the Wallachian and Moldavian lands on the Danube upon the Russian retreat in 1854. Thereafter, Austria remained isolated, which added to the loss of her leading role in the German lands, culminating in the defeat of the Austro-Prussian War in 1866.


Ex Output:
The Austro-Russian alliance finally broke up in the Crimean War: though Russia had helped to completely destroy the Hungarian Revolution of 1848, Austria did not take any action to support her ally, declared herself neutral and even occupied the Wallachian and Moldavian lands on the Danube upon the Russian retreat in 1854


Ex Input:
Question: Was the fortress near Drøbak built before 1800? Passage:Meanwhile, at Oscarsborg Fortress near Drøbak, Colonel Birger Eriksen prepares his undermanned and inexperienced garrison for combat, while receiving reports from the outlying fortresses of incoming German ships. Early on the morning of 9 April, Eriksen spots the German cruiser Blücher entering Drøbak Sound. Despite having received no instructions from Oslo to engage, Eriksen considers the German ship to be hostile and gives the order to fire, and the fortress's guns and torpedo battery sink the Blücher. Prime Minister Nygaardsvold telephones the King, informing him of the impending invasion, and advises him to flee Oslo. The Royal Family boards a train for Hamar, where the Norwegian Parliament convenes to discuss negotiations with Germany. Bräuer meets Oslo's police chief Kristian Welhaven, his intermediary with the Norwegian Cabinet, to reassure them of his desire to negotiate; at the same time, Pohlman receives orders from Berlin to send paratroopers to Hamar to capture the King and the Cabinet. Nasjonal Samling leader Vidkun Quisling proclaims himself Prime Minister over the national radio, and calls upon the Norwegian people to accept the German occupation forces. Bräuer receives instructions from Hitler himself to go directly to the King and convince him to recognise Quisling's government, though Bräuer is convinced that neither Haakon nor the Cabinet will accept this.


Ex Output:

Meanwhile, at Oscarsborg Fortress near Drøbak, Colonel Birger Eriksen prepares his undermanned and inexperienced garrison for combat, while receiving reports from the outlying fortresses of incoming German ships