The boy in the striped pyjamas

I liked the book because it was interesting and also sad at the end. The book is about a nine year old boy called Bruno who is a Jew.He is kept in a concentration camp where the uniform is a striped pyjama. He meets a boy by the name of Shmuel and  form a friendship Bruno is unaware that his new friends father is a German officer.
The end is very sad to find out the end read the book.