Using cyclopentanone as your starting material and using any other reagents of your choice, propose an efficient synthesis for the following compound:

The transformation above can be performed with some reagent or combination of the reagents listed below. Give the necessary reagents in the correct order, as a string of letters $($without spaces or punctuation, such as "EBF"$).$ If there is more than one correct solution, provide just one answer.

A$.$ PhCHO

B$.PhC{H}_{2}Br$

C$.$ LDA

D$.H_3{O}^{+}$

E$.$ NaH

F$.$ Mel