I took the index of your words, transformed the quantity to binary, added 3 zeros, calculated the sha256 digest, took the first Section of the hexadecimal to convert it to binary, extra 3 zeros into the eight digits of the binary and got 00000010011 which translates to 19 in decimal. https://hindibookmark.com/story20471260/detailed-notes-on-copyright-wallet-seed-phrase-out-of-bip39