Solved Count items in inventory?

[fafler]

This one should be trivial, but I haven't been able to figure it out for a couple of days now. I'm hoping someone here has a solution.

How do I count how many of a given item a player has in his inventory?
Like
set {_stoneamount} to amount of cobblestone in players inventory
except that doesn't work.

 

[Syst3ms]

*player's inventory

 

[fafler]

I feel so dumb. But thanks a lot :-D

 

[Syst3ms]

19 characters to solve an issue, that's a new record.