Untitled

<!DOCTYPE html>
<html>
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width">
  <title>JS Bin</title>
</head>
<body>

<script id="jsbin-javascript">
function printLabel(n) {
  if(n === 0) return 'Z';

  if(n <= 26) return String.fromCharCode(64 + n);

  var d = Math.floor(n / 26);
  var m = n % 26;
  if(m === 0) d -= 1;

  var name = String.fromCharCode(64 + d) + printLabel(m);

  return name;
}

console.log(printLabel(26 * 26 + 26 + 1));
</script>


<script id="jsbin-source-javascript" type="text/javascript">function printLabel(n) {
  if(n === 0) return 'Z';

  if(n <= 26) return String.fromCharCode(64 + n);

  var d = Math.floor(n / 26);
  var m = n % 26;
  if(m === 0) d -= 1;

  var name = String.fromCharCode(64 + d) + printLabel(m);

  return name;
}

console.log(printLabel(26 * 26 + 26 + 1));</script></body>
</html>