title: Return min/max number in nested list
body: <p>I'm trying to find the min/max number within a nested list using Linq.</p>
  
  <p>An example class would be:</p>
  
  <pre><code>public class ListA
  {
      public HashSet&lt;HashSet&lt;int&gt;&gt; nestedList;
  
      public ListA()
      {
          nestedList = new HashSet&lt;HashSet&lt;int&gt;&gt;()
          {
              new HashSet&lt;int&gt; { 1, 3, 5, 7 },
              new HashSet&lt;int&gt; { 2, 12, 7, 19 },
              new HashSet&lt;int&gt; { 6, 9 , 3, 14 }
          };
      }
  
      public int MaxNumber
      {
          // return the highest number in list
      }
  }
  </code></pre>
  
  <p>In the example above, the minimum number would be 1 and the max number 19.</p>
  
  <p>I'm struggling to get anything to get valid syntax. Anyone help?</p>