Burundi is a landlocked country in the Eastern Africa Great Lakes region. Neighboring countries include Rwanda, Tanzania, and the Democratic Republic of the Congo. Burundi is hilly and mountainous with access to Lac Tanganyika. The government system is a republic; the chief of state and head of government is the president. Burundi has a traditional economic system in which the allocation of available resources is made on the basis of primitive methods, and many citizens engage in subsistence agriculture. Burundi is a member of the Common Market for Eastern and Southern Africa (COMESA), the East African Community (EAC), and the Economic Community of Central African States (ECCAS).