There are three thin iron wires, the lengths of which are 120 cm, 180 cm, and 300 cm respectively. Now we need to cut them into equal small pieces. There should be no surplus in each piece. What is the longest length of each small piece in centimeters? 
有三根细铁丝，长度分别是120厘米、180厘米、300厘米，现在要把它们截成相等的小段，每根都不能有剩余，每小段最长多少厘米．
<gadget id="calculator">2 * 2 * 3 * 5</gadget>
<output>60</output>

<result>60</result>