You got your hands on some data that was leaked from a social network and you want to help the poor people.
Luckily you know a government service to automatically block a list of credit cards.
The service is a little old school though and you have to upload a CSV file in the exact format. The upload fails if the CSV file contains invalid data.
The CSV files should have two columns, Name and Credit Card. Also, it must be named after the following pattern:
YYYYMMDD
.csv.