I have two columns of data, A and B. I would like to merge these columns such that only the unique values are included in the final list. At the moment, I'm using an array formula from https://www.get-digital-help.com/2009/06/16/extract-an-unique-distinct-list-from-two-columns-using-excel-2007-array-formula/:

```
{=IFERROR(IFERROR(INDEX($A$2:$A$20, MATCH(0, COUNTIF($C$1:C1, $A$2:$A$20), 0)), INDEX($B$2:$B$7, MATCH(0, COUNTIF($C$1:C1, $B$2:$B$7), 0))), "")}
```

While this works wonderfully, I'd like to avoid array formulas if at all possible, as they significantly slow our already crappy PCs. We're also not able to use VBA for reasons, so that's not an option either.

Is there any way to do this?