title: How to pass variable from child to child in Angular2
body: <p>I have three components : <strong>parent (P)</strong>  and <strong>two children (C1)</strong> and <strong>(C2)</strong> 
  (they are <strong>both children of P</strong> component and they are <strong>not nested</strong>) 
  in parent template it looks like </p>
  
  <pre><code>&lt;c1-component&gt;&lt;/c1-component&gt;
  &lt;c2-component&gt;&lt;/c2-component&gt;
  </code></pre>
  
  <p>I have a variable <code>myVar</code> in <code>C1</code> (number), which I want decrease and increase in <code>C2</code> component and give a new value of this variable back to <code>C1</code> (so, I want to pass not a function, but variable). How could I pass this variable from <code>C1</code> to <code>C2</code>?
  I would like to solve this problem without shared services.</p>