Ukrainian Katerina Silvanova and her Russian co-author Elena Malisova never expected their book about two teenagers falling in love would be such a hit – and a reason to flee their countries. A coming-of-age story about the love that grows between two boys at a Soviet pioneer camp, the book, with its two engaging star characters Yura and Volodya, is popular in Russia. But following its publication, author Silvanova was forced to flee to her Ukrainian hometown of Kharkiv, despite it being under Russian attack, while Malisova wound up having to begin a new life in Rostock, Germany. Their first w…