title: C# How to modify text file
body: <p>I need to read accounts.txt and add/change number after password</p>
  
  <p>Here is accounts.txt</p>
  
  <pre><code>user|password
  user1|password1
  </code></pre>
  
  <p>After starting</p>
  
  <pre><code>user|password|1
  user1|password1|1
  </code></pre>
  
  <p>After closing</p>
  
  <pre><code>user|password|0
  user1|password1|0
  </code></pre>
  
  <p>Sorry for my english</p>