title: C and Python - different behaviour of the modulo (%) operation
body: <p>I have found that the same mod operation produces different results depending on what language is being used.</p>
  
  <p>In Python:</p>
  
  <pre><code>-1 % 10
  </code></pre>
  
  <p>produces <strong>9</strong></p>
  
  <p>In C it produces <strong>-1</strong> !</p>
  
  <ol>
  <li>Which one is the right modulo? <br></li>
  <li>How to make mod operation in C to be the same like in Python?</li>
  </ol>