Input: Article: One of the Han's greatest mathematical advancements was the world's first use of negative numbers. Negative numbers first appeared in the Nine Chapters on the Mathematical Art as black counting rods, where positive numbers were represented by red counting rods. Negative numbers are used in the Bakhshali manuscript of ancient India, but its exact date of compilation is unknown. Negative numbers were also used by the Greek mathematician Diophantus in about 275 AD, but were not widely accepted in Europe until the 16th century AD.

Now answer this question: How were negative numbers first described during the Han period?

Output: as black counting rods

Input: Article: The College's endowment is sub-divided into three distinct portfolios: (i) Unitised Scheme a unit trust vehicle for College, Faculties and Departments to invest endowments and unfettered income to produce returns for the long term; (ii) Non-Core Property a portfolio containing around 120 operational and developmental properties which College has determined are not core to the academic mission; and (iii) Strategic Asset Investments containing College's shareholding in Imperial Innovations and other restricted equity holdings. During the year 2014/15, the market value of the endowment increased by 78 million (18%) to 512.4 million on 31 July 2015.

Now answer this question: What was the market value of the endowment the college received on July 31, 2015?

Output: 512.4 million

Input: Article: The house which forms the architectural core of the palace was built for the first Duke of Buckingham and Normanby in 1703 to the design of William Winde. The style chosen was of a large, three-floored central block with two smaller flanking service wings. Buckingham House was eventually sold by Buckingham's descendant, Sir Charles Sheffield, in 1761 to George III for 21,000. Sheffield's leasehold on the mulberry garden site, the freehold of which was still owned by the royal family, was due to expire in 1774.

Now answer this question: Who bought Buckingham House in 1761?

Output:
George III