Copy Sub-Total Values Only

I am entering the ITEM number in column "A". Quantiy is entered in column "B"

There are repetative items withdrawn each day for the same item.
Example: Item X12 QTY 10
ITEM Y22 QTY 7
ITEM X12 QTY 12

What I need is to sort on column "A", sub-total column"B" QTY on item change in column "A".

Then copy only the sub-totals Item and Qty, not the details to Sheet2 Column "A".

Example: X12 22
Y22 7

This will allow me to post the summary (sub-totals) withdrawals only once to the inventory control sheet .