Given a category and a set of five words, find the word from the set that does not belong (i.e. is the least relevant) with the other words in the category. Words are separated by commas.

Example Input: Category: type of sandwich 
Words: submarine, group, club, roll, grilled cheese
Example Output: group

Example Input: Category: secretary duty 
Words: fax, program, file, make coffee, answer
Example Output: program

Example Input: Category: computers 
Words: file, keys, document, fax, ram
Example Output:
fax