I was extremely confused at first because I put in two words in the input box, and clicking 'merge' would do nothing. When I see 'merge', I expect that it will

I was extremely confused at first because I put in two words in the input box, and clicking 'merge' would do nothing. When I see 'merge', I expect that it will somehow merge the two words I've entered. You should change that button or at least add some text so it's a little more obvious what's going on. Or maybe add some code to alert the user that only one word is expected if/when they enter two.