Greece is a country located in Southern Europe on the southern end of the Balkan Peninsula, possessing an archipelago of about 2,000 islands. Greece has land borders with Albania, Macedonia, Bulgaria, Turkey, the Aegean Sea, the Ionia Sea, and the Mediterranean Sea. Greece has a strategic location dominating the Aegean Sea and southern approach to the Turkish Straits. The government system is a parliamentary republic; the chief of state is the president, and the head of government is the prime minister. Greece has a market economy in which the prices of goods and services are determined in a free price system. Greece is a member of the European Union (EU).