datagridview to custom iTextsharp report

Question

C#, visual studio 2015, MS Access database, desktop application - these I have used. I have an existing datagrid view like this:

Type	Item	Price	Quantity
L	A	3	2
M	B	4	3
L	A	5	7
M	B	6	8
L	A	3	5
S	C	2	9
S	C	1	12

I need a report like this:

Sl. No.	Type	Item	TotalPrice	TotalQuantity
1	L	A	11	14
2	M	B	10	11
3	S	C	3	21