There are two colored ribbons, green and yellow. The green one is 30 meters long, and the yellow one is 42 meters long. If they are cut into small sections of equal length, there will be no surplus. How many meters is the longest section?
有绿黄两条彩带绿的长30米，黄的长42米，若分别把它们剪成长度相等的小段，不能有剩余，每段最长多少米呢？
<gadget id="calculator">2 * 3</gadget>
<output>6</output>

<result>6</result>