This was a pretty simple challenge. We are given an xlsx with a huge number of cells with the fake flag format `fake_flag\d`.


Steps to solve:

1. Convert flags.xlsx to a CSV
2. Replace all `,` characters with new lines
3. Do a search with the regex `^(?!fa)`. This is a negative lookahead search <https://stackoverflow.com/a/2967791>

FLAG: `pearl{h3ll_0f_4n_3xc3l}`