title: I want to remove multiple line of text on linux
body: <p>Just like this.
  <br>Before:
  <br></p>
  
  <pre><code>1
  19:22
  abcde
  
  2
  19:23
  
  3
  19:24
  abbff
  
  4
  19:25
  abbc
  </code></pre>
  
  <p>After:</p>
  
  <pre><code>1
  19:22
  abcde
  
  3
  19:24
  abbff
  
  4
  19:25
  abbc
  </code></pre>
  
  <p>I want remove the section having no alphabet like section 2.<br>
  I think that I should use perl or sed. But I don't know how to do.
  I tried like this. But it didn't work.<br></p>
  
  <pre><code>sed 's/[0-9]\n[0-9]\n%s\n//'
  </code></pre>