You have a square piece of paper and you do not know its length or width.

What is the minimum number of folds required in order for the paper to only show 1/15 of its original size, 2/15 of it's original size, 3/15 of its original size, ........, 14/15 of its original size.

Note: You do not know where one-third marks or one-fifth marks lie on this piece of paper therefore you must use folds to mark these areas. You are allowed to use folds as guides to make other folds.