exrex "flag\{wa{0}e[^abcdrfghijknmopqrstuvwxyz]c(((o)))(?=[a-z])[^a-ln-z]e_to_dc{0}ctf{1}\}" -o out.txt - you can list all possible words accepted by regex with this tool
exrex "flag\{wa{0}e[^abcdrfghijknmopqrstuvwxyz]c(((o)))(?=[a-z])[^a-ln-z]e_to_dc{0}ctf{1}\}" -o out.txt