Question: What was the smallest denomination of the official currency of the Hong Kong Special Administrative Region from 1863 to 1866?

full_context: Document 1: Taxation in Hong Kong: Under Article 108 of the Basic Law of Hong Kong, the taxation system in Hong Kong is independent of, and different from, the taxation system in mainland China. In addition, under Article 106 of the Hong Kong Basic Law, Hong Kong enjoys independent public finance, and no tax revenue is handed over to the Central Government in China. The taxation system in Hong Kong is generally considered to be simple, transparent and straightforward among jurisdictions in the world. Taxes are collected through the Inland Revenue Department (IRD).
Document 2: Bank of China (Hong Kong): Bank of China (Hong Kong) Limited (BOCHK, ) is the second-largest commercial banking group in Hong Kong in terms of assets and customer deposits, with more than 300 branches in Hong Kong. It was established on 1 October 2001 from a merger of 12 subsidiaries and associates of the Bank of China in Hong Kong, and listed on the Hong Kong Stock Exchange in October 2002. As of the end of 2003, the bank had HK$763 billion in assets and earned net profit of HK$8 billion in 2003. Its head office is in the Bank of China Tower in Central.
Document 3: Hong Kong one-mil coin: The one mil coin was the smallest denomination of the Hong Kong dollar from 1863 to 1866, after this date it was no longer issued but may have circulated much longer. Its value was one tenth of a cent, or a thousandth of a dollar. Despite being minted under British rule, they did not feature the reigning monarch as all other coins did, due to the hole in the middle.
Document 4: Ten pence (British coin): The British decimal ten pence (10p) coin – often pronounced "ten pee" – is a unit of currency equalling ten one-hundredths of a pound sterling. Its obverse has featured the profile of Queen Elizabeth II since the coin's introduction in 1968, replacing the two shilling coin in preparation for decimalisation in 1971. Four different portraits of the Queen have been used on the coin, with the latest design by Jody Clark being introduced in 2015. The second and current reverse, featuring a segment of the Royal Shield, was introduced in 2008.
Document 5: Sovereign (British coin): The sovereign is a gold coin of the United Kingdom, with a nominal value of one pound sterling. Prior to 1932 it was a fully circulating coin within Britain's then Gold Standard currency. Today it is used as a bullion coin and is sometimes mounted in jewellery. The most valuable sovereign is the British Edward VIII 1937 struck for Edward VIII who abdicated, therefore these coins never entered circulation, and an example of one was purchased at auction in 2014 for £516,000.
Document 6: Brunei dollar: The Brunei dollar (Malay: "ringgit Brunei", currency code: "BND"), has been the currency of the Sultanate of Brunei since 1967. It is normally abbreviated with the dollar sign $, or alternatively B$ to distinguish it from other dollar-dominated currencies. It is divided into 100 "sen" (Malay) or "cents" (English). The Brunei dollar is issued by the Autoriti Monetari Brunei Darussalam (Monetary Authority of Brunei Darussalam).
Document 7: Clearing House Automated Transfer System: The Clearing House Automated Transfer System, or CHATS, is a Real Time Gross Settlement (RTGS) system for the transfer of funds in Hong Kong. It is operated by Hong Kong Interbank Clearing Limited, a private company jointly owned by the Hong Kong Monetary Authority (HKMA) and the Hong Kong Association of Banks. Transactions in four currency denominations may be settled using CHATS: Hong Kong dollar, renminbi, euro, and US dollar. In 2005, the value of Hong Kong dollar CHATS transactions averaged HK$467 billion per day, which amounted to a third of Hong Kong's annual Gross Domestic Product (GDP); the total value of transactions that year was 84 times the GDP of Hong Kong.
Document 8: Half-cent coin (Netherlands): The half-cent coin was a Dutch coin used from 1818 to 1940. It was the smallest-denomination coin of the decimal Dutch guilder until its withdrawal from circulation after the German occupation of the Netherlands in 1940. It was nicknamed "Halfje", similar to the Kwartje (the suffix "-je" is a diminutive in the Dutch language, similar to the English "-ie").
Document 9: Newfoundland twenty-five cents: Although twenty-cent coins were required during the reign of King George V, arrangements were being made to replace the denomination. The Ottawa Mint was going to start producing Newfoundland’s coins and Canadians did not like the Newfoundland twenty-cent piece. Newfoundland coins circulated throughout Canada as well and the Newfoundland twenty-cent coin was often confused with Canadian twenty-five cent coins. The Canadian government convinced Newfoundland’s government to discontinue the twenty-cent coin. A twenty-five coin was introduced and struck on the same standard as the corresponding Canadian coin. The obverse of the coin was exactly the same as that of the Canadian twenty-five cent coin.
Document 10: Barbadian dollar: The dollar has been the currency of Barbados since 1935. The present dollar has the ISO 4217 code "BBD" and is normally abbreviated with the dollar sign "$" or, alternatively, "Bds$" to distinguish it from other dollar-denominated currencies. It is divided into 100 cents. On 22 October 2010 it was reported that the international rating agency Standard & Poor's (S&P) rated the currency of Barbados as "BBB-/A-3".
Document 11: Fillér: The fillér ] was the name of various small change coins throughout Hungarian history. It was the ⁄ subdivision of the Austro-Hungarian and the Hungarian korona, the pengő and the forint. The name derives from the German word "Vierer" that means "number four" in English. Originally it was the name of the four-kreuzer coin. Due to significant inflation that took place after the fall of communism, fillér coins are no longer in circulation. The last fillér coin, worth 50 fillér (0.5 forint) was removed from circulation in 1999. However, it continues to be used in calculations, for example in the price of petrol (e.g. 310.9 forint), or in the prices of telephone calls.
Document 12: Economy of Hong Kong: As one of the world's leading international financial centres, Hong Kong's service-oriented economy is characterized by its low taxation, almost free port trade and well established international financial market. Its currency, called the Hong Kong dollar, is legally issued by three major international commercial banks, and pegged to the US dollar. Interest rates are determined by the individual banks in Hong Kong to ensure it is fully market-driven. There is no officially recognised central banking system, although Hong Kong Monetary Authority functions as a financial regulatory authority. When destabilising factors are hitting the financial market of Hong Kong, they will be monitored and inspected by the Hong Kong Monetary Authority, the financial regulatory agency in Hong Kong. Electronic finance trading is evolutionarily impacting the financial market of Hong Kong.
Document 13: British twenty-five pence coin: The commemorative British decimal twenty-five pence (25p) coin was issued in four designs between 1972 and 1981. These coins were a post-decimalisation continuation of the traditional crown, with the same value of a quarter of a pound sterling. Uniquely in British decimal coinage, the coins do not have their value stated on them. This is because previous crowns rarely did so.
Document 14: Hong Kong dollar: The Hong Kong dollar (; lit. "Harbour Money"; sign: HK$; code: HKD) is the official currency of the Hong Kong Special Administrative Region. It is subdivided into 100 cents. The Hong Kong Monetary Authority is the governmental currency board and also the "de facto" central bank for the Hong Kong dollar.
Document 15: Hong Kong: Hong Kong, officially the Hong Kong Special Administrative Region of the People's Republic of China, is an autonomous territory south to Mainland China and east to Macao in East Asia. With around 7.2 million Hong Kongers of various nationalities in a territory of 1,104 km, Hong Kong is the world's fourth most densely populated country or territory.
ground_truth: one mil coin