'''
Given an integer (signed 32 bits), write a function to check whether it is a power of 4.

Example 1:

Input: 16
Output: true
Example 2:

Input: 5
Output: false
Follow up: Could you solve it without loops/recursion
'''



class Solution:
    def isPowerOfFour(self, n: int) -> bool:
         return n>0 and (n & n-1) == 0 and n & (0xAAAAAAAA) == 0
        