Every challenge runs your code by calling a function. You must define a function named solution(...) that returns the answer.
Key rule: use return — not print(). The grader only checks the returned value; anything you print is ignored.
✗ Won't be graded
def solution(a, b):
print(a + b)
✓ Correct
def solution(a, b):
return a + b
What the grader sends
Your function is called with the challenge's test inputs, for example:
solution(3, 5) # expects 8
Match the parameter names and count shown in the challenge description, and always finish with a return.