Which of these Southeast European countries has the largest population?

Which country has a population of over 50 million? What is the approximate population of Japan? What is the approximate population of Brazil? What is the approximate population of Russia? Which country is larger in terms of land area, Japan or the United Kingdom? Which of the following countries is the largest in terms of land area in Africa? Which country is larger in terms of land area, Kazakhstan or the Democratic Republic of the Congo? Which of the following countries is the largest in terms of land area in South America?