title: How cv2.waitKey(1) & 0xff == ord('q') works?
body: <p>How this line works?</p>
  
  <p>As I know so far, the output of <code>cv2.waitKey(number)</code> for all every <code>int</code> number is <code>-1</code>, and <code>0xff</code> is a hexadecimal number that is equals to <code>255</code> in decimal numbers.</p>
  
  <p><code>-1 &amp; 0xff</code> is equals to <code>255</code> in decimal numbers.</p>
  
  <p>Also, <code>ord('q')</code> is equal to <code>113</code>.</p>
  
  <p>But now, I don't know why <code>255 == 113</code>?</p>