Hungary is a landlocked country in Central Europe bordering Austria, Croatia, Romania, Serbia, Slovakia, Slovenia, and Ukraine. Hungary's landscape consists of flat to rolling plains divided in two by its main waterway, the Danube. The government system is a parliamentary democracy; the chief of state is the president, and the head of government is the prime minister. Hungary has made the transition from a centrally planned economic system to a market economy in which the prices of goods and services are determined in a free price system. Hungary is a member of the European Union (EU).