Children line up to do morning exercises, no matter counting from the left or smiling from the right, they are ranked fifth. How many children are there in this row?
小朋友排队做早操，无论从左数还是从右手笑笑都排在第5位，这排小朋友有多少人．
<gadget id="calculator">5 - 1</gadget>
<output>4</output>

<gadget id="calculator">4 * 2</gadget>
<output>8</output>

<gadget id="calculator">8 + 1</gadget>
<output>9</output>

<result>9</result>