Add two months data within loop - BPC Script Logic

Hi All,

I am trying to write script logic to add 2 months data.

Problem is, I can calculate it using TVML when one month is selected but when multiple months are selected, it does not work.

eg.

If user run package with 4 months selected (M1, M2, M3 and M4)

Month1 Results = Month1 value

Month 2 Results = Month 1 value (calculated from above step) + Month 2 Value

Month 3 Results = Month 2 Value (calculated from above step) + Month 3 Value

Month 4 Results = Month 3 Value (calculated from above step) + Month 4 Value

Data sample.

If M1=10, M2=10, M3 = 10, M4 = 10

Results:

M1 = 10, M2 = 20, M3 = 30, M4 = 40

Logic I am using now: