There are three iron wires, one is 15 meters long, the other is 18 meters long, and the other is 27 meters long. Cut them into small sections of the same length. No excess is allowed. How many meters is the longest section?
有三根铁丝，一根长15米，一根长18米，一根长27米，把它们截成同样长的小段，不许有剩余，每段最长有几米？
<result>3</result>