There are two iron wires, one is 18 meters long and the other is 27 meters long. Cut them into small pieces of the same length. No surplus is allowed. How many pieces should they be cut into at least?
有两根铁丝，一根长18米，另一根长27米，把它们截成同样长的小段，不许有剩余，至少截成多少段？
<gadget id="calculator">3 * 3</gadget>
<output>9</output>

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

<gadget id="calculator">27 / 9</gadget>
<output>3</output>

<gadget id="calculator">2 + 3</gadget>
<output>5</output>

<result>5</result>