Https://www.codecademy.com/paths/computer-science/tracks/cspath-flow-data-iteration/modules/dspath-lists/lessons/python-functions-lists-cc/exercises/every-three-nums

Help, i don’t know how to do it

https://www.codecademy.com/paths/computer-science/tracks/cspath-flow-data-iteration/modules/dspath-lists/lessons/python-functions-lists-cc/exercises/every-three-nums