Budding ballerinas

Almost all girls at some time dream of becoming a famous ballerina. For most, the dream fades and gets packed away with the worn-out ballet pumps. But for some who have the ambition, the guts and the stamina, it becomes a reality. They start by getting accepted into a ballet school .... and one of the best in the world is the Kirov in the Russian city of St Petersburg. The BBC's Linda Duffin reports