You must be very familiar with derivative in math,and I guarantee that you can work out the derivative easily. Generally speaking,the last problem is the most difficult problem only a few can work out. However,it is not the case in this contest designed by Samuel. Give you 1 number n,and 2 extra numbers a and b you can work this problem out. For example,f(x)=ax^b,the 2 class derivative is f''=a*b*(b-1)x^(b-2),here n means n class. Here all the numbers are integers.