Macro to merge 3 rows multi times, columns A:K only

[Steve]

I have data in every 3 rows (5,8,11, etc), through column K. I need to keep
columns L & M as is.

I'd like a macro to merge A5:K7, A8:K10, A11:K13, etc, through a specific
number of rows (the max number of rows would change depending on which sheet
I was using) . Meaning one sheet would be through row 32 ( the last of the
merged rows) another sheet the last of the merged rows would be through row
50, etc. I could identify the max row in a cell if the macro could use that
number when it's run.

Thanks,

Steve