Question: when was the country that includes Kroh formed through unification?

full_context: Document 1: Khong District, Laos: Khong is a district ("muang") of Champassack Province in southwestern Laos. The district borders Cambodia in the far south and is famous for the Khonephapheng Waterfalls and the Si Phan Don (4000 Islands) area.
Document 2: British Empire: Following the defeat of Japan in the Second World War, anti-Japanese resistance movements in Malaya turned their attention towards the British, who had moved to quickly retake control of the colony, valuing it as a source of rubber and tin. The fact that the guerrillas were primarily Malayan-Chinese Communists meant that the British attempt to quell the uprising was supported by the Muslim Malay majority, on the understanding that once the insurgency had been quelled, independence would be granted. The Malayan Emergency, as it was called, began in 1948 and lasted until 1960, but by 1957, Britain felt confident enough to grant independence to the Federation of Malaya within the Commonwealth. In 1963, the 11 states of the federation together with Singapore, Sarawak and North Borneo joined to form Malaysia, but in 1965 Chinese-majority Singapore was expelled from the union following tensions between the Malay and Chinese populations. Brunei, which had been a British protectorate since 1888, declined to join the union and maintained its status until independence in 1984.
Document 3: Chuping: Chuping is a small town in Perlis, Malaysia. It is located to the northeast of Kangar, the state capital. The town has 22,000 hectares of plantations, which consist of rubber estates and the largest sugar cane plantation in Malaysia.
Document 4: Kroh: Kroh or Keruh, now, known as Pengkalan Hulu, is a town within Hulu Perak district, in northern Perak, Malaysia bordering Thailand and also the state of Kedah. The nearest town on the Thailand side is Betong in Yala province.
Document 5: Batu Kawa: Batu Kawa is a suburban area located right next to the 3rd Mile Roundabout in Kuching Division, State of Sarawak in Malaysia. The town is administratively under the Kuching South City Council. The Pan Borneo Highway passing through the area links Kuching City with Bau, Lundu and Sematan further west. This place is also known to have many hornet nest.
Document 6: Kapar: Kapar is a town in the Klang District of Selangor, Malaysia. The Sultan Salahuddin Abdul Aziz Power Station is located not far from town. The Kapar River which flows nearby the town centre empties into the Straits of Malacca.
Document 7: History of Malaysia: Japanese invasion during World War II ended British domination in Malaysia. The subsequent occupation of Malaya, North Borneo and Sarawak from 1942 to 1945 unleashed nationalism. In the Peninsula, the Malayan Communist Party took up arms against the British. A tough military response was needed to end the insurgency and bring about the establishment of an independent, multi-racial Federation of Malaya on 31 August 1957. On 22 July 1963, Sarawak was granted a self - governance. The following month on 31 August 1963, both North Borneo and Singapore were also granted self - governance and all states began to formed Malaysia on 16 September 1963. Approximately two years later, the Malaysian parliament passed a bill without the consent of signatory of Malaysia Agreement 1963 to separate Singapore from the Federation. A confrontation with Indonesia occurred in the early - 1960s. Race riots in 1969 led to the imposition of emergency rule, and a curtailment of political life and civil liberties which has never been fully reversed. Since 1970 the ``Barisan Nasional coalition ''headed by United Malays National Organisation (UMNO) has governed Malaysia until the
Document 8: Myanmar: British colonial rule introduced Western elements of culture to Burma. Burma's education system is modelled after that of the United Kingdom. Colonial architectural influences are most evident in major cities such as Yangon. Many ethnic minorities, particularly the Karen in the southeast and the Kachin and Chin who populate the north and northeast, practice Christianity. According to the The World Factbook, the Burman population is 68% and the ethnic groups constitute 32%. However, the exiled leaders and organisations claims that ethnic population is 40%, which is implicitly contrasted with CIA report (official US report).
Document 9: Jalan Wang Kelian: Jalan Wang Kelian, Federal Route 226 (formerly Perlis State Route R15), is a federal road in Perlis, Malaysia. It is also a main route to Wang Prachan and Satun, Thailand via Wang Prachan Road (National highway 4184). Jalan Wang Kelian is notorious for its narrow and dangerous sharp corners. The Kilometre Zero of the Federal Route 226 starts at the Malaysia-Thailand border near Wang Kelian Checkpoint, Perlis.
Document 10: Malaysia: Malaysia has its origins in the Malay kingdoms which, from the 18th century, became subject to the British Empire, along with the British Straits Settlements protectorate. Peninsular Malaysia was unified as the Malayan Union in 1946. Malaya was restructured as the Federation of Malaya in 1948, and achieved independence on 31 August 1957. Malaya united with North Borneo, Sarawak, and Singapore on 16 September 1963 to become Malaysia. In 1965, Singapore was expelled from the federation.The country is multi-ethnic and multi-cultural, which plays a large role in its politics. About half the population is ethnically Malay, with large minorities of Malaysian Chinese, Malaysian Indians, and indigenous peoples. While recognising Islam as the country's established religion, the constitution grants freedom of religion to non-Muslims. The government system is closely modelled on the Westminster parliamentary system and the legal system is based on common law. The head of state is the king, known as the Yang di-Pertuan Agong. He is an elected monarch chosen from the hereditary rulers of the nine Malay states every five years. The head of government is the Prime Minister. The country's official language is Malaysian, a standard form of the Malay language. English remains an active second language.
Document 11: Private school: After Malaysia's independence in 1957, the government instructed all schools to surrender their properties and be assimilated into the National School system. This caused an uproar among the Chinese and a compromise was achieved in that the schools would instead become "National Type" schools. Under such a system, the government is only in charge of the school curriculum and teaching personnel while the lands still belonged to the schools. While Chinese primary schools were allowed to retain Chinese as the medium of instruction, Chinese secondary schools are required to change into English-medium schools. Over 60 schools converted to become National Type schools.
Document 12: British Empire: Most former British colonies and protectorates are among the 53 member states of the Commonwealth of Nations, a non-political, voluntary association of equal members, comprising a population of around 2.2 billion people. Sixteen Commonwealth realms voluntarily continue to share the British monarch, Queen Elizabeth II, as their head of state. These sixteen nations are distinct and equal legal entities – the United Kingdom, Australia, Canada, New Zealand, Papua New Guinea, Antigua and Barbuda, The Bahamas, Barbados, Belize, Grenada, Jamaica, Saint Kitts and Nevis, Saint Lucia, Saint Vincent and the Grenadines, Solomon Islands and Tuvalu.
Document 13: 2018 Malaysian general election: This marked a historic defeat for the ruling Barisan Nasional coalition, which had been the governing party of Malaysia and its predecessor state, Malaya, since the country's independence in 1957. This makes Mahathir Mohamad the next Prime Minister of Malaysia and, at 92 years old, the oldest head of government in the world, although he has indicated he would give way within a few years to jailed opposition leader Anwar Ibrahim after seeking a royal pardon for him.
Document 14: Perlis: Perlis, also known by its honorific title Perlis Indera Kayangan, is the smallest state in Malaysia. It lies at the northern part of the west coast of Peninsular Malaysia and has the Satun and Songkhla Provinces of Thailand on its northern border. It is bordered by the state of Kedah to the south. It was called Palit () by the Siamese when it was under their influence. Perlis had a population of 227,025 as of 2010.
Document 15: Malaysia: The education system features a non-compulsory kindergarten education followed by six years of compulsory primary education, and five years of optional secondary education. Schools in the primary education system are divided into two categories: national primary schools, which teach in Malay, and vernacular schools, which teach in Chinese or Tamil. Secondary education is conducted for five years. In the final year of secondary education, students sit for the Malaysian Certificate of Education examination. Since the introduction of the matriculation programme in 1999, students who completed the 12-month programme in matriculation colleges can enroll in local universities. However, in the matriculation system, only 10 per cent of places are open to non-bumiputera students.
ground_truth: 1963
sub_queries: Kroh >> country Answer: Malaysia
In what year did the unification of Malaysia happen? Answer: 1963