LaTeX template for the Telegram group "Retos Matemáticos" AUTHORS: Henry Díaz Bordón; José Manuel Sánchez Muñoz. LICENSE: CC BY-SA 4.0 (Creative Commons Attribution-ShareAlike 4.0 International). VERSION: v1.1.0 The code within this package is the one employed for the creation of the final solutions of the cha- llenges proposed in the Telegram group "Retos Matemáticos" - with more than 1300 members! -, by José Manuel Sánchez Muñoz. The RetoMatematico.cls class, among other characteristics, changes the dimensions of the document to letter-format paper, the font to Palatino Linotype- through the mathpazos package -, and places de- tails such as the ISSN and link of the group in the margins. For a more detailed description, the user may check the package documentation and example document.