There are 3 gram, 5 gram, and 1 gram weights. Choose one or several of them. How many objects with different weights can be directly weighed on the balance?
有3克、5克、1克的砝码各一个，选其中的一个或几个，在天平上能够直接称出多少种不同重量的物体？
<gadget id="calculator">3 + 3 + 1 + 1 + 1</gadget>
<output>9</output>

<result>9</result>