<p>Write a function that adds two numbers. You should not use + or any arithmetic operators.</p>

<p><strong>Example:</strong></p>

<pre>
<strong>Input:</strong> a = 1, b = 1
<strong>Output:</strong> 2</pre>

<p>&nbsp;</p>

<p><strong>Note: </strong></p>

<ul>
	<li><code>a</code>&nbsp;and&nbsp;<code>b</code>&nbsp;may be 0 or negative.</li>
	<li>The result fits in 32-bit integer.</li>
</ul>