mit="event.preventDefault(); checkPrime();">
        <input
            type="text"
            id="is_prime"
            placeholder="Insert your number here"
            aria-label="Insert your number here"
            required>
        <button type="submit">Check</button>
    </form>

    <div id="result">Result: </div>
<hr>
    <div>
      <h2>More cases</h2>
      <button type="button" onclick="check100()">Check for 100 random numbers</button>
      <ul id="100-results"></ul>
      <button type="button