Measure grouping in WEBI

Hi ,

I have data in table like below

Product Order count Cost

A 1 20

A 2 30

B 3 40

B 4 50

expected results

Product Total (Order Count* Cost)

A 80

B 320

but getting like below

Product Total (Order Count* Cost)

A 150

B 630

Please help me how we can solve in report level