I took the index of your words, converted the number to binary, additional 3 zeros, calculated the sha256 digest, took the first Portion of the hexadecimal to convert it to binary, extra three zeros towards the 8 digits on the binary and acquired 00000010011 which interprets to 19 in decimal. https://zenwriting.net/keenanctdp/h1-b-unlocking-the-power-of-bip39-a-comprehensive-look-at-word-lists-and