Categorize the input news's emotional tone into one of three groups.
Options: negative, positive

Founded in 1983, Costco Wholesale Corp. ( COST , Financial) has become one of the great retail success stories in U.S. history. As the leading warehouse club in the country, Costco has 828 stores worldwide (as of March 3), with most sales derived in the United States (572 stores) and Canada (105 stores).
positive