insert rows based on text values in cells

Hello and thanks in advance,

I regularly run a report that comes out in a slightly different format each time depending on whether or not there is data for specific criteria. for instance (sample attached): criteria a, b, and c are in rows, 1, 2, and 3 in columns. a, b, and c are expected to repeat themselves several times. if there is no data in one instance of b then you may see something like abcacabc.

I'd like to loop through each row in column a, check to make sure that it is the correct value (either a, b, or c) and if not, insert a blank row so I can then copy the data to my final project without having to worry about formatting.

the example above would then become abca cabc

thanks again!