The runway of the playground is 30 meters long, and a colorful flag is inserted every 6 meters. There are two rows in total. How many flags are needed at most?
操场跑道长30米，每隔6米插一面彩旗，共插两排，最多需要多少面旗？
<gadget id="calculator">30 / 6</gadget>
<output>5</output>

<gadget id="calculator">5 + 1</gadget>
<output>6</output>

<gadget id="calculator">6 * 2</gadget>
<output>12</output>

<result>12</result>