I took the index from the words, transformed the selection to binary, extra three zeros, calculated the sha256 digest, took the initial Element of the hexadecimal to transform it to binary, added 3 zeros on the eight digits from the binary and obtained 00000010011 which interprets to 19 in decimal. https://loanbookmark.com/story19064441/the-fact-about-valid-bip39-seed-phrase-that-no-one-is-suggesting