In a season lasting 50 days, every day some chrysanthemum flowers bloom on a tree. On the first day if ?n? flowers bloomed and on the next day all the flowers that bloomed on the previous day except one fell off. (No flower fell off on the first day). If the number of flowers that fell off on the second day is 5 and it is known that on any given day in that season the difference between the number of flowers that bloomed on that day and that of the number of flowers that fell off on that day is constant.