Need help on Mohawk!?

I recently decided that I wanted a n�e hairstyle and decided on the Mohawk!! There is a problem tho, I have enough hair on the top of my head, about 3 inches standing up, but the back of my head I have only about 3/4 of an inch.... Any suggestions on what I should do? I can only have it up for about two and half months also; only the summer... :( if worst come to worst I will just shave it all off... Thanks guys and gals!!!