title: Regex to remove EVEN lines
body: <p>I need help to build a regex that can remove EVEN lines in a plain textfile. </p>
  
  <p>Given this input:</p>
  
  <blockquote>
    <p>line1<br>
    line2<br>line3<br>line4<br>line5<br>line6<br></p>
  </blockquote>
  
  <p>It would output this:</p>
  
  <blockquote>
    <p>line1<br>line3<br>line5<br></p>
  </blockquote>
  
  <p>Thanks !</p>