Given two integers a and b, return the sum of the two integers without using the operators `+` and `-`.
a
b
Example 1:
Input: a = 1, b = 2
a = 1, b = 2
Output: 3
3
Example 2:
Input: a = 2, b = 3
a = 2, b = 3
Output: 5
5
-1000 <= a, b <= 1000