Number of literals in the given boolean expression

Count the number of literals in the following expression :

F = AB' + BC' + CD' + DE'

According to me, the answer should be 8. But my solution suggests that the answer should be 6. Can anyone help me out. What am I doing wrong?

Does your material use the (strange) convention of notating $$\neg A$$ as $$A'$$?
If so, there are 6 literals (5 without the LHS). If $$A'$$ is distinct from $$A$$, there are 9 (8 without LHS) and the solution book is wrong.