10 children stand in a row to do exercises, every two adjacent children are 2 meters apart, what is the length of the exercise team?
10位小朋友站成一列做操，每相邻两位小朋友相隔2米，做操的队伍长多少米．
<gadget id="calculator">10 - 1</gadget>
<output>9</output>

<gadget id="calculator">9 * 2</gadget>
<output>18</output>

<result>18</result>