I took the index from the words, converted the amount to binary, included three zeros, calculated the sha256 digest, took the first Portion of the hexadecimal to transform it to binary, added 3 zeros for the 8 digits of your binary and got 00000010011 which interprets to 19 in decimal. https://push2bookmark.com/story18999521/5-simple-techniques-for-bip39-word-list-pdf