title: Obfuscate C code
body: <p>I came across this obfuscated code recently: </p>
  
  <pre><code>#include &lt;stdio.h&gt;
  
  #define _____(i,s,o,g,r,a,m)(i##r##s##o)
  #define _ _____(m,i,n,u,a,l,s)
  
  int _()
  {
      printf("Hello World!");
      return 0;
  }
  </code></pre>
  
  <p>What is happening here? How is it that <code>_()</code> is <code>main()</code>?</p>
  
  <p>Edit:
  I was looking for the 'technical term' that has been used here.</p>