Sample drawing procedure with container details

Dear All,

I have a scenario -" raw materials coming in drum or other container, out of the total lot size system consider square root of (n+1) for calculating no of drums for sample and then from each sample drum they pick 50 ml or 100 ml  ( fixed).

How to map this. I tried this with sample drawing procedure with P2 in formula, but its not working.

Please let me know the steps

Thanks

Vivek