Another condition is that both columns A and B are "compacted" at the top of the columns.
If there are 10 words in either column A or B, then these words will appear in rows 1 through 10. If there are 10 words in column A and 100 words in column B, then column A will have the words in rows 1 through 10 and column B will have the words in rows 1 through 100
