Find frequency of letters appearing in 5-letter words in the English language

Inspired by Wordle game

List of words in English https://github.com/dwyl/english-words/blob/master/words_alpha.txt

List of words in PTBR https://www.ime.usp.br/~pf/dicios/index.html

Then generated 5-letter words with

grep -E '^[[:alpha:]]{5}$' words_alpha.txt > words_len5.txt

Two words that contain the 10 most common letters (ENG) are: UTILE and SONAR