<!DOCTYPE html>
<html>
<head>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.12.2/jquery.min.js"></script>
<script>
$(document).ready(function(){
$("button").click(function(){
$("ul li:first").hide();
});
});
</script>
</head>
<body>
<p>List 1:</p>
<ul>
<li>Coffee</li>
<li>Milk</li>
<li>Tea</li>
</ul>
<p>List 2:</p>
<ul>
<li>Coffee</li>
<li>Milk</li>
<li>Tea</li>
</ul>
<button>Click me</button>
</body>
</html>