Suppose A=1, B=2, C=3, ..., Z=26. Then, ETUDE is an interesting word. It has 5 letters, it starts and ends with the 5th letter of the alphabet, and E+T+U+D+E=5+20+21+4+5=55. What other words both start and end with the Xth letter of the alphabet and add up to XX, where X is the number of letters in the word and XX is X concatenated with X? (For ETUDE, X=5.)