dataGridView to dataGridView

Question

I have a datagrid view like this:

Item	Price
A	3
B	4
A	5
B	6
A	3
C	2
C	1

I need a new datagridview like this:

Sl. No.	Item	Total Price
1	A	11
2	B	10
3	C	3

How is it possible?