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: Which category contains a 2 year old tree?, Context: To accurately map the Amazon's biomass and subsequent carbon related emissions, the classification of tree growth stages within different parts of the forest is crucial. In 2006 Tatiana Kuplich organized the trees of the Amazon into four categories: (1) mature forest, (2) regenerating forest [less than three years], (3) regenerating forest [between three and five years of regrowth], and (4) regenerating forest [eleven to eighteen years of continued development]. The researcher used a combination of Synthetic aperture radar (SAR) and Thematic Mapper (TM) to accurately place the different portions of the Amazon into one of the four classifications.
Example Output: 2

Example Input: From what era, once thought devoid of animal life, was evidence of grazer populations discovered?, Context: Some paleontologists suggest that animals appeared much earlier than the Cambrian explosion, possibly as early as 1 billion years ago. Trace fossils such as tracks and burrows found in the Tonian period indicate the presence of triploblastic worms, like metazoans, roughly as large (about 5 mm wide) and complex as earthworms. During the beginning of the Tonian period around 1 billion years ago, there was a decrease in Stromatolite diversity, which may indicate the appearance of grazing animals, since stromatolite diversity increased when grazing animals went extinct at the End Permian and End Ordovician extinction events, and decreased shortly after the grazer populations recovered. However the discovery that tracks very similar to these early trace fossils are produced today by the giant single-celled protist Gromia sphaerica casts doubt on their interpretation as evidence of early animal evolution.
Example Output: the Tonian period

Example Input: What skirmish occurred in early 1900s?, Context: When Russia invaded the Turkish Balkans in 1853, fears of Russian dominance in the Mediterranean and Middle East led Britain and France to invade the Crimean Peninsula to destroy Russian naval capabilities. The ensuing Crimean War (1854–56), which involved new techniques of modern warfare, and was the only global war fought between Britain and another imperial power during the Pax Britannica, was a resounding defeat for Russia. The situation remained unresolved in Central Asia for two more decades, with Britain annexing Baluchistan in 1876 and Russia annexing Kirghizia, Kazakhstan, and Turkmenistan. For a while it appeared that another war would be inevitable, but the two countries reached an agreement on their respective spheres of influence in the region in 1878 and on all outstanding matters in 1907 with the signing of the Anglo-Russian Entente. The destruction of the Russian Navy by the Japanese at the Battle of Port Arthur during the Russo-Japanese War of 1904–05 also limited its threat to the British.
Example Output:
Russo-Japanese War

