Gigi's home is located on the grid with the points (-6, 2), (-1, 2), (-7, 4) and (0, 4). She is planning to paint the entire roof of her home. Each unit on the coordinate grid represents 5 feet. Each can of paint can paint up to 45 feet of open space. How many cans of paint must Gigi purchase to paint the entire roof of her room?

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