A 3-layer hollow square has 28 people in the innermost layer. How many people are there in this square?
一个3层中空方阵，最内层共有28人，这个方阵共有多少人．
<gadget id="calculator">28 + 4</gadget>
<output>32</output>

<gadget id="calculator">32 / 4</gadget>
<output>8</output>

<gadget id="calculator">8 + 2</gadget>
<output>10</output>

<gadget id="calculator">10 * 4</gadget>
<output>40</output>

<gadget id="calculator">40 - 4</gadget>
<output>36</output>

<gadget id="calculator">10 + 2</gadget>
<output>12</output>

<gadget id="calculator">12 * 4</gadget>
<output>48</output>

<gadget id="calculator">48 - 4</gadget>
<output>44</output>

<gadget id="calculator">28 + 36 + 44</gadget>
<output>108</output>

<result>108</result>