Given a number N, return a string consisting of "0"s and "1"s that represents its value in base -2 (negative two). The returned string must have no leading zeroes, unless the string is "0". Example 1: Input: 2 Output: "110" Explantion: (-2) ^ 2 + (-2) ^ 1 = 2 Example 2: Input: 3 Output: "111" Explantion: (-2) ^ 2 + (-2) ^ 1 + (-2) ^ 0 = 3 Example 3: Input: 4 Output: "100" Explantion: (-2) ^ 2 = 4 Note: 0 <= N <= 10^9