title: Java: Comparing two lists
body: <p>I have two lists. 
  For example: </p>
  
  <pre><code>A = {21, 41, 96, 02}
  B = {21, 96, 32, 952, 1835}
  </code></pre>
  
  <p>What I want is this as a result: <code>R = {32, 952, 1835}</code></p>
  
  <p>Like this: 
  <img src="https://i.stack.imgur.com/CJj8U.png" alt="Example Picture"></p>
  
  <p>After this I want to add the result <code>R</code> to <code>A</code>:</p>
  
  <pre><code>A = {21, 41, 96, 02, 32, 952, 1835}
  </code></pre>