Input rows:

days Qty [Aging Stock] priority

269 285 305 1

287 30 300 2

output:

269 285 305 1 -- same as input row1

269 20 305 2 -- few qty from row-2 to fill row1 qty

287 10 300 2 -- remaining qty from row-2

Explantion for output:

ouput row 1) same as input row

ouput row 2) in input row 1 in 269 days still we can store more 20 qty (305-285) , So from input row 2 values we can store 20 Qtys from 30 Qty

ouput row 3) remaining 10qtys from input row 2