Description

Given an integer n, return true if it is a power of two. Otherwise, return false.

An integer is a power of two if there exists an integer x such that n == 2x.

Input format / Clarification:

• Line 1: Integer n

Examples

Input:
1
Output:
true

Input:
16
Output:
true

Input:
3
Output:
false

Note:

Your program must print true or false so it can be compared with the expected output.