This usually happens when you have left a "print" statement (or whatever the equivalent in your language is - displaying to console/stdout etc.) somewhere in your code.

Try removing anything that logs output to screen, it should work then.

Hi! I think I have solved the exercise correctly but when I try to send it I get the following error when executing the code with a very large list (10000000)

"Maximum buffer size reached (1.5 MiB)"