Given two integers a and b, return the sum of the two integers without using the operators + and -.

Example 1:

Input:
1 2
Output: 3

Example 2:

Input:
2 3
Output: 5

Constraints:

• -1000 ≤ a, b ≤ 1000

Input format: Two space-separated integers on one line.

Output format: Their sum.