For each given state, click all states that are TWO states away from that state. In other words, for each given state, click all the states that border all the states that border that state.
For example, if I put Washington, you would put all the states that border Idaho, AND all the states that border Oregon (Montana, Wyoming, Utah, Nevada, Oregon, Idaho, and California).
In the example above, DO put Oregon or Idaho, as Washington borders Idaho, which borders Oregon.
Arizona DOES count as bordering Colorado, and same with the other corners.