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<html lang="en">
<head>
  <meta charset="utf-8">
  <title>Help</title>
  <script>
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      if (navigation.canGoBack) {
        navigation.back();
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</head>
<body>
  <section>
    <h1>Help</h1>
    <button type="button" onclick="goback()">Go to the previous page</button>
  </section>
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