<!DOCTYPE html>
<html>
  <head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <link rel="stylesheet" href="/static/bootstrap/css/bootstrap.min.css">
    <title>为什么要打开 /flag 😡</title>
  </head>
  <body>
    <div class="container px-3 pt-3">
        <h1>为什么要打开 /flag 😡</h1>
        <div>
            <form method=post enctype=multipart/form-data>
            <div class="form-group">
                <label for="file" class="f