(2) The transformation of our cities into smart cities is becoming more real everyday thanks to 5G technology. Creating and optimizing 5G network distribution with an algorithm is the goal of the fourth edition of Reply Code Challenge 2021, the team based competition organized by Reply to introduce new generations of talent to digital and coding culture. The competition, open to coders from all over the world, will take place online on Thursday, March 11, 2021. There are two challenges that are taking place at the same time: the Standard Edition, aimed at university students and professionals, and the Teen Edition, open to young people between 14 and 19 years old.