Given a question and a context passage, generate the answer having the word or phrase from the context passage. Here, the answer should be a shortest continous span from the passage.

Example Input: Context: The Egyptian Peasant is a book by Henry Habib Ayrout about the life of the Egyptian peasant (fellah).
Question: Who was the writer of The Egyptian Peasant?
Example Output: henry habib ayrout

Example Input: Context: Johann Bayer used the Greek letters Alpha to Eta to label the most prominent eight stars in the constellation, designating two stars as Delta (named Delta1 and Delta2). John Flamsteed numbered fourteen stars, discerning a third star he named Delta3; his star 12 Canis Minoris was not found subsequently. In Bayers 1603 work Uranometria, Procyon is located on the dogs belly, and Gomeisa on its neck. Gamma Canis Minoris, Epsilon Canis Minoris and Eta Canis Minoris lie nearby, marking the dogs neck, crown and chest respectively. Although it has an apparent magnitude of 4.34, Gamma Canis Minoris is an orange stellar classification giant star of spectral class K3-III C, which lies away. Its colour is obvious when seen through binoculars. It is a multiple system, consisting of the spectroscopic binary Gamma A and three optical companions, Gamma B, magnitude 13; Gamma C, magnitude 12; and Gamma D, magnitude 10. The two components of Gamma A orbit each other every 389.2 days, with an eccentric orbit that takes their separation between 2.3 and 1.4 astronomical units (AU). Epsilon Canis Minoris is a yellow bright giant of spectral class G6.5IIb of magnitude of 4.99. It lies from Earth, with 13 times the diameter and 750 times the luminosity of the Sun. Eta Canis Minoris is a giant of spectral class F0III of magnitude 5.24, which has a yellowish hue when viewed through binoculars as well as a faint companion of magnitude 11.1. Located 4 arcseconds from the primary, the companion star is actually around 440 AU from the main star and takes around 5000 years to orbit it.
Question: What is 13 times the diameter of the sun?
Example Output: epsilon canis minoris

Example Input: Context: New software is able to analyze exactly how many hairs there are in a patch of skin and could help in testing the effectiveness of baldness treatments and depilatory creams, say Australian researchers. Researchers from CSIRO Mathematical and Information Sciences in prefix = st1 /Sydneyreport their findings in the November issue of the journalSkin Research and Technology. The software, developed with a UKcompany, will make it easier for researchers developing hair removal creams to accurately assess how well they work, says Dr Pascal Vallotton. "Up to now they were counting the number of hairs that survived after treatment by hand. That's hard work and it's difficult because you may count a hair twice or you may miss it." he said. The software relies on images captured by a small flatbed scanner pressed onto the skin. Using a mathematical algorithm , the software then identifies and traces each individual hair based on an understanding of a hair's unique features, such as its straightness. The software is able to distinguish between hairs and other features on the skin such as wounds or moles . "Our skin irregularities make it difficult to say this is a hair or this is a mole," Dr Vallotton said. Comparison between earlier and later images can also determine if hair is growing quickly or slowly, he says. Unfortunately, to check the accuracy of the software, the researchers still had to adopt the old-fashioned method of counting hairs, helped by volunteers from neighboring labs who put their skins on the line for science. "We had 12 volunteers, mostly from neighboring labs, and we acquired images of hair before and after treatment," Dr Vallotton said. To ensure an accurate count, the individual hairs had to be marked off as they were counted, but after such a laborious process, the researchers were pleased to discover the software results were comparable to the manual count. Dr Vallotton says the software could also be useful in testing the effectiveness of balding treatments and counting or tracing substances other than hairs, that are long and thin and otherwise difficult to image.
Question: What plays a key role in counting the number of hairs with the software?
Example Output:
a scanner.