user: Who built Sigiriya fortress in Sri Lanka?

assistant: <think>
It is likely that the area around Sigiriya may have been inhabited since prehistoric times. There is clear evidence that the many rock shelters and caves in the vicinity were occupied by Buddhist monks and ascetics from as early as the 3rd century BC. The earliest evidence of human habitation at Sigiriya is the Aligala rock shelter to the east of Sigiriya rock, indicating that the area was occupied nearly five thousand years ago during the Mesolithic Period.

Buddhist monastic settlements were established during the 3rd century BC in the western and northern slopes of the boulder-strewn hills surrounding the Sigiriya rock. Several rock shelters or caves were created during this period. These shelters were made under large boulders, with carved drip ledges around the cave mouths. Rock inscriptions are carved near the drip ledges on many of the shelters, recording the donation of the shelters to the Buddhist monastic order as residences. These were made in the period between the 3rd century BCE and the 1st century AD.

In 477 AD, Kashyapa I, the king’s son by a non-royal consort, seized the throne from King Dhatusena, following a coup assisted by Migara, the King’s nephew and army commander. The rightful heir, Moggallana, fearing for his life, fled to South India. Afraid of an attack by Moggallana, Kashyapa moved the capital and his residence from the traditional capital of Anuradhapura to the more secure Sigiriya. During King Kashyapa’s reign (477 to 495 AD), Sigiriya was developed into a complex city and fortress. Most of the elaborate constructions on the rock summit and around it, including defensive structures, palaces, and gardens, date from this period.</think>
King Kashyapa developed Sigiriya city and fortress.

user: How do you play chess?

assistant: Chess is a two-person board game, where the objective of the game is to capture your opponents King. The King is just one of sixteen pieces that each player can use during the game. The other fifteen pieces include: Eight pawns, two rooks, two knights, two bishops, and a queen. The pieces are placed on an eight by eight, square board in a fixed starting position. The game begins by the player using the white pieces moving one of their pieces to another square. Each player will then alternate playing one move turns. Each piece has a set of legal moves that it can perform. For example, a bishop can only move diagonally on squares of its same color, whereas rooks can only move vertically or horizontally. The goal of the game is to use your pieces in a strategic manner that ultimately leads to your opponent's King being captured. The most common way to achieve this is by using your pieces to capture your opponent's pieces that are defending the King, and then exploiting this weakness to attack the King. While it's important to play on the offensive, it's equally as important to understand your opponent's strategy, so that you can properly defend against their attempts to capture your own King.

user: What are the three branches of the US Federal Government?

assistant: The US Constitution divides the federal government into three branches: legislative, executive and judicial.  This ensures that no individual or group will have too much power.