Comparing two columns in gsheet

Question

I have two columns that I have imported from 2 different files named as Listing Id and LID. These two columns contain same type of data and I want to find the common value from the column and stored in third column matching LIds which i did using Vlookup. Now corresponding to each column i.e Listing Id and Lid there is inventory id. What i want is to copy the data of LID correspondence inventory id in the Listing id correspondence Inventory. How can I approach this problem? I have tried with match() function but not geeting the way out.

Here is screenshot of the problem enter image description here

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As it can be seen that listing_id in red has corresponding inventory value and listing id in blue have corresponding inventory value. The problem is that there exist some common listing id (in blue and red as well)for which there is no available data of inventory value in blue. I have to get it from red inventory value and update it to blue.