How to get the distinct counts from two DataSets in SSRS Reports?

I have two SharePoint List Name as A and B. A List has columnsCountry Name,ID and B List has Column New ID

List A

Country Name : ID

AU                       001

AU                       002

AU                       007

MY                       003

IN                        004

List B

New ID

002

003

005

006

007

I have created 2 data sets , dsA and dsB .Using these data sets how to calculate the distinct count of ID's.

I want to create a report in SSRS mentioned  below

Distinct Counts for Country Name

AU   2

MY   1

IN   0

Any workaround ? Please give your valuable suggestions