There are two logs, one 12 meters long and the other 9 meters long. To cut them into small pieces of the same length, and there is no surplus, how many meters is the longest of each piece of logs.
有两根圆木，一根长12米，另一根长9米．要把它们截成同样长的小段，而且没有剩余，每一段圆木最长多少米．
<result>3</result>