<!DOCTYPE html>
<html>
<body>
<p>Integers are considered accurate up to 15 digits.</p>
<button onclick="myFunction()">Try it</button>
<p id="demo"></p>
<script>
function myFunction() {
var x = 999999999999999;
var y = 9999999999999999;
document.getElementById("demo").innerHTML = x + "<br>" + y;
}
</script>
</body>
</html>