In the image above vertex \(1,2\) and \(3\) are kings because they can each get to every other vertex in at most \(2\) steps. Lets take a look at vertex \(1\), \(1\rightarrow3\)\(1\rightarrow3\rightarrow2\), and \(1\rightarrow3\rightarrow4\). The reason why vertex \(4\) is not a king is because it would take more than \(2\) steps to reach vertex \(2\).