I took the index of your words, transformed the selection to binary, added three zeros, calculated the sha256 digest, took the very first Portion of the hexadecimal to transform it to binary, included three zeros to the eight digits on the binary and obtained 00000010011 which interprets to 19 in https://active-bookmarks.com/story19510366/bip39-phrase-generator-can-be-fun-for-anyone