Classify each of the following as either a city or a country:  Seoul, Shanghai, Sao Paolo, Singapore, Sweden.

Seoul is the largest city in South Korea and also the capital.  Shanghai is the most populous city in China and is also known as "The Pearl of Asia."  Sao Paolo is a city in the Brazilian state of the same name, Sao Paolo and is named after an Apostle, Saint Paul of Tarsus.  Singapore is simultaneously a city, state, and country.  Sweden is a country which has produced many world-renowned pop singers and bands including Abba.