I took the index in the words, transformed the number to binary, extra a few zeros, calculated the sha256 digest, took the first Element of the hexadecimal to convert it to binary, added 3 zeros into the 8 digits in the binary and bought 00000010011 which interprets to 19 in https://cyberbookmarking.com/story18777398/considerations-to-know-about-bip39-word-list-pdf