The politics of Argentina take place in the framework of what the Constitution defines as a federal presidential representative democratic republic, where the President of Argentina is both Head of State and Head of Government. Legislative power is vested in the two chambers of the Argentine National Congress. The Judiciary is independent, as well as the Executive and the Legislature. Elections take place regularly on a multi-party system. In the 20th century, Argentina experienced significant political turmoil and democratic reversals. Between 1930 and 1976, the armed forces overthrew six governments in Argentina; and the country alternated periods of democracy (1912–1930, 1946–1955, and 1973–1976) with periods of restricted democracy and military rule. Following a transition that began in 1983, full-scale democracy in Argentina was reestablished. Argentina's democracy endured through the 2001–02 crisis and to the present day; it is regarded as more robust than both its pre-1983 predecessors and other democracies in Latin America. The government structure of Argentina is a democracy; it contains the three branches of government. The current Chief of State and Head of Government is President Alberto Fernández. Legislative Branch is a bicameral Congress, which consists of the Senate (72 seats), presided by the vice-president, and the Chamber of Deputies (257 seats), currently presided by Cecilia Moreau of the Buenos Aires Province. The General Auditing Office of the Nation and the Ombudsman are also part of this branch. Deputies serve for 4 years, while Senators serve for 6 years. The Judiciary Branch is composed of federal judges and others with different jurisdictions, and a Supreme Court with five judges, appointed by the President with approval of the Senate, who may be deposed by Congress. Argentina is divided into 23 Provinces, the equivalent of States, and one autonomous district, CABA, inside the Buenos Aires province. Because of Argentina’s federal structure, every province has its own constitution, and authorities.