Excel how to add values in Column C if combination of values in column A and C is unique

I have an Excel table listing rooms, type of windows and how much windows are in that room:
Example:

        COL-A| COL-B  | Col-C
Row1 |  Room | Window | Qty
Row2 |  A    | W1     | 1
Row3 |  A    | W2     | 1
Row4 |  A    | W1     | 1
Row5 |  B    | W1     | 1
Row6 |  B    | W1     | 1
Row7 |  B    | W1     | 1
Row8 |  B    | W1     | 1
...

I need to get a list telling how many Windows of each typ there is in each room:

       COL-A | COL-B  | Col-C
Row1 |  Room | Window | Qty
Row1 |  A    | W1     | 2
Row1 |  A    | W2     | 1
Row1 |  B    | W1     | 4
...

It means I have to add values in Column C (QTY) if the combination of values in Column A and B are the same.

I have tryed all sort of cformula combinations like =SUMIFS(UNIQUE(A2:A100);AND;UNIQUE(B:100)) However without succes.

Any help would be appreciated

>Solution :

I just inserted a Pivot Table, and clicked on all fields to add to report, this is the screenshot of the result:

(The sigma values "Sum of Quantity is generated automatically, that’s how basic this is)