I took the index on the words, converted the selection to binary, included three zeros, calculated the sha256 digest, took the initial Section of the hexadecimal to convert it to binary, additional 3 zeros to the 8 digits with the binary and bought 00000010011 which translates to 19 in decimal. https://bookmarksparkle.com/story18982213/invalid-bip39-phrase-things-to-know-before-you-buy