Exact degrees

A number (x) is termed a perfect power if there exist integers (a) and (b) such that (x = a^b) and (b > 1). Your task is to determine how many such numbers exist within the interval (A $\le$ x $\le$ B).

Input

You will be given two integers, (A) and (B), where the absolute values do not exceed (10^14).

Output

Output the count of perfect powers that lie within the interval (A $\le$ x $\le$ B).

Examples