Personally, I don't like the wording of your question, but I can see what it is using.
Have you made a picture for your work?
Within the 40 ft by 130 ft that you can put the shelter, along the 40 ft, you can put the shelter in two ways:
One of the left (pink) and one on the right (bluish).
Now, how can you move the shelter in the unshaded area? Try moving the shelter down and count them. (move by 1 ft each time)
Can you get the 22?