https://stackoverflow.com/questions/41424312/arnold-cat-map-decryption-code
https://stackoverflow.com/questions/49332374/program-that-decodes-a-message-in-fortran?fbclid=IwAR14WLebnZ5zNbK25Rsvc225CV6q-qxCfIYyZcoQnNGT6jnyYhDUFqIrA5o
https://8gwifi.org/ecfunctions.jsp?fbclid=IwAR09x4MKxdDK0t7N_0SwleMC3AYrOn7B9P4ShNfEpIYy3XLEMOr7Qb7fQ4A
https://www.paep.sg.mai.gov.pt/Documents/EP_PR2026-Texto%20de%20entrada.pdf