How to filter out unnecessary input value in email (modx revo + formit)?

Question

MODX

There is the following construction: there are two products that can be selected by checkboxes. When choosing a product, with the help of js, an additional input appears, where you need to specify its quantity (default is "1")

Using the formit plugin, I implemented it this way:

<!-- Ручка -->
<input type="hidden" name="pen[]" value="">
<input type="checkbox" id="pen" name="pen[]" value="Ручка"  
 onclick="showHide('pen-input');" >
<label for="pen">Ручка</label>

<!-- Всплывающий инпут Ручки -->
<div  id="pen-input" style="visibility:hidden">
<input type="text"  id="pen-number" name="pen-number" value="1">
 </div>


<!-- Товар-2 -->
<input type="hidden" name="pencil[]" value="">
<input type="checkbox" id="pencil" name="pencil[]" value="Карандаш"  
 onclick="showHide('pencil-input');" >
<label for="pencil">Карандаш</label>

<!-- Всплывающий инпут Карандаша -->
<div  id="pencil-input" style="visibility:hidden">
<input type="text"  id="pencil-number" name="pencil-number" value="1">
 </div>

The chunk describing the letter from the server is as follows:

Покупатель выбрал:<br />  
 —  <br />
 — 

As a result, if the buyer has chosen both goods and indicated their quantity (default is "1"), then the type of letter is as follows: The
buyer has chosen:
Pen - 1
Pencil - 1
it leaves a counter with "1" by default: The
buyer chose:
Pen - 2
- 1
I can't figure out how to avoid getting the amount of unselected item in the email.
In which direction to dig, how to be?

Answer 1

Solution from Pavel Romanov:
In a chunk:

Answer 2

Crutch variant, for the normal organization it is necessary to smoke to dock.

Покупатель выбрал:<br />