Project Euler #29: Distinct powers

_{This problem is a programming version of Problem 29 from projecteuler.net}

Consider all integer combinations of for and :

If they are then placed in numerical order, with any repeats removed, we get the following sequence of 15 distinct terms:

How many distinct terms are in the sequence generated by for and ?

Input Format

Input contains an integer

Constraints

Output Format

Print the answer corresponding to the test case.

Sample Input

Sample Output