Cut three small sticks of 40cm, 20cm, and 16cm into small pieces of the same length, and there should be no surplus. What is the longest length of each small stick in cm?
把三根分别长40cm、20cm、16cm的小棒，截成同样长的小段，不能有剩余，每根小棒最长多少cm．
<gadget id="calculator">2 * 2</gadget>
<output>4</output>

<result>4</result>