The politics of the state of San Marino take place in a framework of a unitary assembly-independent representative democratic republic, whereby the Captains Regent are the heads of state and heads of government. The country has a multi-party system. Executive power is exercised by the government. Legislative power is vested in both the government and the Grand and General Council. The judiciary is independent of the executive and the legislature. San Marino was originally led by the Arengo, initially formed with the heads of each family. In the 13th century, power was given to the Great and General Council. In 1243, the first two Captains Regent were nominated by the council, and that system is still in use today. The Grand and General Council The legislature of the republic is the Grand and General Council (Consiglio grande e generale). The council is a unicameral legislature which has 60 members with elections occurring every 5 years under a majoritarian representation system in a sole national constituency. Citizens eighteen years or older are eligible to vote. Besides general legislation, the Grand and General Council approves the budget and elects the Captains Regent, the State Congress, the Council of Twelve, the Advising Commissions, and the Government Unions. The council also has the power to ratify treaties with other countries. The council is divided into five different Advising Commissions consisting of 15 councilors which examine, propose, and discuss the implementation of new laws that are on their way to being presented on the floor of the council. The Captains Regent Every six months, the Council elects two Captains Regent to be the heads of state. The foundational theory was to create a balance of power or, at least, reciprocal control. They serve a 6-month term. The investiture of the Captains Regent takes place on April 1 and October 1 in every year. Once this term is over, citizens have 3 days in which to file complaints about the Captains' activities. If they warrant it, judicial proceedings against the ex-head(s) of state can be initiated. The practice of dual heads of state, according to the principle of Collegiality, as well as the frequent re-election of same, are derived directly from the customs of the Roman Republic. The council is equivalent to the Roman Senate; the Captains Regent, to the consuls of ancient Rome. The Congress of State The Congress of State is the government of