title: How to get distinct values from two List<string>?
body: <p>I have two list.</p>
  
  <pre><code>List&lt;string&gt; a = new List&lt;string&gt;();
  List&lt;string&gt; b = new List&lt;string&gt;();
  
  a.Add("a");
  a.Add("b");
  a.Add("c");
  b.Add("a");
  b.Add("c");
  </code></pre>
  
  <p>I want Distinct value into a new list.</p>