SP4415 INTEGER1 - Power of Integer

For a given positive integer _y_(_y_ > 1), if we can find a largest integer k and a smallest positive integer _x_, such that _x^k=y_, then the power of _y_ is regarded as _k_. Calculate the sum of the power of the integers from a to b. (2

The input consists of multiple test cases. For each test case, there is one line containing two integers _a_ and _b_. End of input is indicated by a line containing two zeros.

For each test case, output the sum of the power of the integers from _a_ to _b_.