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

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

Examples

Example 1

Input:  n = 1
Output: true

2⁰ = 1

Example 2

Input:  n = 16
Output: true

2⁴ = 16

Example 3

Input:  n = 3
Output: false

Constraints

• -2³¹ <= n <= 2³¹ - 1