how to compare similairity of one column data from different excel files

Lei

I have three excel files. They all have a column named "word" with 300 rows.

for example:
file A (word column)               file B (word column)                  file C (word column)
book                                      pen                                          desk
plate                                      book                                        dictionary
studio                                    studio                                       book

I want to compare similarity of these three columns. Which operator is suitable, data to similarity operator, and how to realize it?

Is anyone who can give me ideas or rapidminer code?
Thank you.