Nauru is a republic with a parliamentary system of government. The president is both head of state and head of government. A 19-member unicameral parliament is elected every three years. The parliament elects the president from its members, and the president appoints a cabinet of five to six members. Nauru does not have any formal structure for political parties, and candidates typically stand for office as independents; fifteen of the 19 members of the current Parliament are independents. Alliances within the government are often formed on the basis of extended family ties rather than party affiliation.