Instructions: Given a list of steps and an additional step, determine where the step fits into the original list of steps. A correct answer, correctly places the given step into the set of steps so that it creates a new plausible set of steps. Output must be formatted as 'After step n', where n is the step number after which the given additional step is to be inserted.
Input: Steps: (1) A person breathes in oxygen (2) The oxygen is moved into the bloodstream (3) Circulates through the body (4) The cells in the body exchange the oxygen with carbon dioxide (5) The bloodstream carries the carbon dioxide back to the lungs (6) The lungs expel the carbon dioxide through the nose and mouth.  
Where does the following step fit into the given list of steps: The oxygen passes through the bronchial tubes to the lungs 
Output:
 After step 1. 