Uruguay is a South American country on the Atlantic Ocean squeezed between Argentina to its west and Brazil to its north. It is the second smallest country in South America, after Suriname. More than 80 percent of Uruguay's population is of Spanish and Italian descent, making it one of the most homogenous countries in South America. It is also one of the region's most politically stable countries. For a brief period in the 19th century, Uruguay was part of Brazil, and it claims about 140 square miles of Brazil's southern border city of Santana do Livramento. Though Brazil does not recognize the claim, Uruguay has avoided taking the dispute to the International Court of Justice, and relations between the two countries have remained peaceful. Meanwhile, disputes with Argentina over the environmental effects of Uruguay's economic activities on the Uruguay River, which separates the two countries, have strained relations. Uruguay is a full member of the Common Market of the South and has veto power in trade negotiations involving the bloc. The country is a major exporter of soybeans and wheat as well as meat and dairy products. Additionally, Uruguay's river system is navigable; the Uruguay River and Rio de la Plata flow to the Atlantic Ocean, giving the country's products cheap transportation access to international markets.