During the school sports meeting, on a circular runway with a circumference of 400 meters, a red flag is inserted every 8 meters, and then a yellow flag is inserted every 2 meters between two adjacent red flags, how many yellow flags are inserted in total.
校运会期间，在周长400米的环形跑道上，每隔8米插一面红旗，然后在相邻两面红旗之间每隔2米插一面黄旗，则共插黄旗多少面．
<gadget id="calculator">8 / 2</gadget>
<output>4</output>

<gadget id="calculator">4 - 1</gadget>
<output>3</output>

<gadget id="calculator">400 / 8</gadget>
<output>50</output>

<gadget id="calculator">3 * 50</gadget>
<output>150</output>

<result>150</result>