With traceability, a small marrow-washing pill can wash six attributes, and a large marrow-washing pill only needs two at the end to wash the innate attribute to 15 points (because the marrow-washing pill can only be used when the innate attribute is greater than or equal to 3 points), and then it needs only 6 small marrow-washing pills, 8 large marrow-washing pills and one small marrow-washing pill.