title: Project euler number 10#
body: <pre><code>The sum of the primes below 10 is 2 + 3 + 5 + 7 = 17.
  
  Find the sum of all the primes below two million.
  </code></pre>
  
  <p>And my answer is:</p>
  
  <pre><code>bool IsRishoni;
  int soap = 0;
  for (int i = 3; i &lt; 2000000; i++)
  {
      IsRishoni = true;
      for (int a = 2; (a &lt;= Math.Sqrt(i)) &amp;&amp; (IsRishoni); a++)
      {
          if (i % a == 0)
              IsRishoni = false;
      }
      if (IsRishoni)
      {
          soap = i + soap;
      }
  }
  Console.WriteLine(soap + 2);
  Console.ReadLine();
  </code></pre>
  
  <p>Why is this not working? the answer I got is 1179908154 ... help please.</p>