Compare Two list and sum values based on all matching values and by month

Hi All,

I am trying to write a formula, which will compare two lists and based on all matches, it sums up their values by month.

I have searched lots of websites but unable to find any solution.

I have attached a sample file for your reference. In the sample file I have highlighted the boxes with the correct amount that should be there for Month 1 and onwards.

The first list is in Summary Tab : Column A (If I add more elements in Column A, the sum of values should be for all those elements. The 2nd list is in Data tab: Column D.

Your help will be really appreciated.