I wrote:

They each belong to a different node. To distinguish them, the node index together with the variable is stored in the list.

Is it correct? How about

They each belong to a different node. To distinguish them, the node index is stored in the list, together with the variable

or even:

They each belong to a different node. To distinguish them, together with the variable, the node index is also stored in the list.

Actually I don't know the position of together with variable in this sentence. Should it immediately follows the name with which it comes or it can be after the verb?