You can avoid the need for the `num_of_stops` variable by writing it like this:

```
def calc_num_stops(subway, start_line, start_station, end_line, end_station)
  if start_line == end_line
    start_station_index = subway[start_line.to_sym].index(start_station)
    stop_station_index = subway[end_line.to_sym].index(end_station)
    (stop_station_index - start_station_index).abs
  else
    num_start_line_stops = stops_to_park(subway, start_line, start_station)
    num_end_line_stops = stops_to_park(subway, end_line, end_station)
    (num_start_line_stops + num_end_line_stops).abs
  end
end
```

Recall that the last line executed in a method becomes the return value, if you don't explicitly type `return`.