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<title>30DaysOfJavaScript</title>
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<h1>30DaysOfJavaScript:03 Day</h1>
<h2>Introduction</h2>
<button onclick="alert('Welcome to 30DaysOfJavaScript!');">Click Me</button>
<script src="./helloworld.js"></script>
<script src="./introduction.js"></script>
<script src="./variable.js"></script>
<script src="./main.js"></script>
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