How to flip bits in C#?
<p>I have a binary number in the form of a string as</p>

<pre><code>string input = "10110101101";
</code></pre>

<p>Now I need to flip (<code>0 to 1</code> and <code>1 to 0</code>) the <em>first 3 bits</em> of it.</p>

<p>The resultant output will be <strong>010</strong>10101101</p>

<p>How to do so in C#?</p>