User talk:Derian miguel ramirez vargas

May 2019
Hello, I'm Serols. I wanted to let you know that I reverted one of your recent contributions —specifically this edit to Luhn algorithm— because it did not appear constructive. If you would like to experiment, please use the sandbox. If you have any questions, you can ask for assistance at the Help desk. Thanks. Serols (talk) 18:43, 2 May 2019 (UTC)