Cuba is a one-party Communist state; the Cuban Communist party (PCC) is the only legal political party. The country is governed under the constitution of 1976. The government is led by Fidel Castro, who was prime minister from 1959 until the post was abolished in 1976 and became president of the Council of State and president of the Council of Ministers in 1976. (The office of president is both head of state and head of government.) Legislative authority resides in the National Assembly of People's Power. The 609 assembly seats are filled by direct election from selected candidate lists; members serve for five-year terms. Administratively, Cuba is divided into 15 provinces and the special municipality of the Isle of Youth.