Add this print(g, m, n) as the first line in step function and you'll see the input. Check this out: https://docs.codewars.com/training/troubleshooting#print-input

The problem is in your code, it ignores the boundaries and returns numbers outside the range [m, n].

Language, values, Sample tests or Attempt tests?

there is a test case where only two numbers are comming but there is requerement for three numbers