In a pile of 10 books, there are 3 of Economics , 3 of computers , 2 of engineering and 2 of medicine .Taking from above, there is a medicine book between a Economics and engineering book, an Economics book between an engineering and a medicine book, a computers book between a medicine and an engineering book, an engineering book between two computers books and two computers books between an economics and an engineering book. Book of which subject is at the seventh position from the bottom ?