Untitled

<!DOCTYPE html>
<title>Foo</title>
<div>Expected value: <b>3748986303764</b></div>
<div>Actual value: <b id="ret"></b></div>
<script>
  var base62decode = function(a,b,c,d){for(b=c=(a===(/\W|_|^$/.test(a+="")||a))-1;d=a.charCodeAt(c++);)b=b*62+d-[,48,29,87][d>>5];return b};

  document.getElementById("ret").innerHTML = base62decode("140bytes")
</script>