SUMIF for dynamic range of weeks

[deadlyliquidxxx]

So here is the data in the workbook attached.

I need it to know what the first 4 weeks of selling are, which is bigger than the other weeks for product A, and B for stores going across A and B. (take note that its 1000s of products and hundreds of stores)
So basically I need a formula smart enough to take in data from the 4 big weeks of big selling and also take in the previous little weeks of selling but disregard a fifth week of big selling for a particular store.
So basically the sumif formula somehow needs to know an average or something and know what to add up based for the store and to disregard the and 5th big number.
Book1.xlsx

Thank you all in advance

[FDibbins]

This seems to work...
=SUM(OFFSET(IF(U$2="Store B",$K4,$B4),0,COUNTIFS($C$2:$S$2,U$2,$C4:$S4,">0")-1,1,-4))

However, I dont get the logic behind including H5 in the calc?