Have you even trained for this? ahahah
I can see you walking 36 miles, but running it is a different story.
When I ran a 13 miler, I had around a 6:50 mile pace(average), when I did my marathon, i had a 9:00 mile pace, as I hit the wall at around the 19th mile. It is not easy at all, and I was tempted to throw my thumb up and hitch a ride to the finish line.
Oh well, I admire your willingness to do it, hopefully you trained for it.