Need a macro to fill down to the last row that could vary from 50 rows

Good Afternoon,

I am trying to figure out a macro problem. I need a macro to fill down to the last row of a spreadsheet that could vary from 50 rows to 10000. When I record my macro, it only recognizes the exact cell that I autofil down to, thus making it fail if the next worksheet has a different number of rows. Any help on how to get my macro to recognize exactly where to stop versus stopping at a specific cell that was recorded would be greatly appreciated. Thank you!

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