Sudan is a country located in Northern Africa bordering the Red Sea. Neighboring countries include Central African Republic, Chad, Egypt, Eritrea, Ethiopia, Libya, and South Sudan. The geography of Sudan is generally flat with mountains in the east and west and annual flooding in the south due to the Nile River system. The government system is the Government of National Unity (GNU). The chief of state and head of government is the President. Sudan has a largely traditional economy in which the majority of the citizens rely on agriculture but there is limited central planning by the government. Sudan is a member of the African Union (AU), African Economic Community (AEC), Council of Arab Economic Unity (CAEU), and Common Market for Eastern and Southern African (COMESA).