Reconciling A Master Worksheet Against Three Other Worksheets?

I have four worksheets and they are named: P (the master spreadsheet), and then A, G, and S (which, combined, should contain all the values on P). These spreadsheets are identically formatted. Column A in each spreadsheet has a Name, and column B has a quantity associated with that name. There are no column titles or headers.

Basically, I need to ensure A, G and S role up into P.

I'd like to create a macro that will identify instances where Column A (the Name) on the master spreadsheet has a match with Column A (the name) on any other spreadsheet. Then when there is a match, I want to reconcile Columns A (the names) and B (the quantities) on the master spreadsheet against its corresponding values on the other spreadsheets. In my ideal scenario, a new worksheet would be created showing:

Column A: Contains the values from Spreadsheet P, Column A

Column B: Contains the value from Spreadsheet P, Column B

Column C: Blank

Column D: Contains any matching value to Spreadsheet P, Column A, but otherwise states "No Match"

Column E: Lists the corresponding value to Column D, but otherwise states "No Match"

Column F: Equals Column B minus Column E, but otherwise states "No Match"

I've tried applying examples from other threads but they are so customized/specific to people's individual needs that I've been unable to make them work for my more simplistic example above.