rectangular flower bed with a length of 5 meters and a width of 3 meters is how many meters is needed to wrap a rope 10 meters long around the flower bed.
一个长5米，宽3米的长方形花坛，用一根长10米的绳子绕花坛一周还差多少米．
<gadget id="calculator">5 + 3</gadget>
<output>8</output>

<gadget id="calculator">8 * 2</gadget>
<output>16</output>

<gadget id="calculator">16 - 10</gadget>
<output>6</output>

<result>6</result>