In this task, you're given a passage, further information available on a particular linked term from the statement, and a question. Your job is to generate the answer to the question by using the information provided. If there is no clear answer obtainable, output 'none'.

Ex Input:
Passage: The spotted green pigeon or Liverpool pigeon (Caloenas maculata) is a species of pigeon which is most likely extinct. It was first mentioned and described in 1783 by John Latham, who had seen two specimens of unknown provenance and a drawing depicting the bird. The taxonomic relationships of the bird were long obscure, and early writers suggested many different possibilities, though the idea that it was related to the Nicobar pigeon (C. nicobarica) prevailed, and it was therefore placed in the same genus, Caloenas. Today, the species is only known from a specimen kept in World Museum, Liverpool. Overlooked for much of the 20th century, it was recognised as a valid extinct species by the IUCN Red List only in 2008. In 2014 a genetic study confirmed it as a distinct species related to the Nicobar pigeon, and showed that the two were the closest relatives of the extinct dodo and Rodrigues solitaire.
Link Information: The animal order Columbiformes is also constituted of pigeons and doves, and includes about 42 genera and 310 species.
Question: How many species of pigeons are there?

Ex Output:
Answer: 310

Ex Input:
Passage: Pinza sang once again under the baton of Toscanini in 1935, this time with the New York Philharmonic Orchestra, as the bass soloist in performances of Beethoven's Missa Solemnis. One of these performances was broadcast by CBS and preserved on transcription discs; this recording has been issued on LPs and CDs. He also sang in Toscanini's February 6, 1938, NBC Symphony Orchestra's broadcast performance of Beethoven's Ninth Symphony. These performances both took place in Carnegie Hall. In March 1942, Pinza was arrested at his home and unjustly detained 3 months on Ellis Island with hundreds of other Italian-Americans who were suspected of supporting the Axis. The incident was extremely traumatic for Pinza, and he suffered from severe depression for years afterward. In October 1947, he performed the role of Mephistopheles in Guonod's Faust opposite his daughter, soprano Claudia Pinza Bozzolla, as Marguerite at the San Francisco Opera.
Link Information: Ludwig van Beethoven (; ; baptised 17December 177026March 1827) Question: How old would Beethoven have been if he could have watched Ezio perform with the NY Philharmonic Orchestra?

Ex Output:
Answer: 165

Ex Input:
Passage: The Bad Pass Trail, also known as the Sioux Trail, was established by Native Americans on the border of present-day Montana and Wyoming as a means of access from the Bighorn Basin in Wyoming to Bison-hunting grounds in the Grapevine Creek area of Montana. Marked by stone cairns, the trail led across Bad Pass and was established in pre-Columbian times. After Europeans arrived in the area it was frequented by fur trappers and mountain men, beginning in 1824. Trappers assembled pack trains at the junction of the Shoshone River and the Bighorn River, using the Bad Pass Trail to avoid Bighorn Canyon. The trail ended at the mouth of Grapevine Creek on the Bighorn, from which the pack train could float down the Bighorn on rafts to the Yellowstone River and then to the Missouri and on to St. Louis.
Link Information: The Shoshone River is a 100 mi long river in northern Wyoming Question: Which river that trappers assembled pack trains at the junction of is longer?

Ex Output:
Answer: The Bighorn River