In a connected graph, bridge is an edge whose removal disconnects a graph. Which one of the following statements is true?

A graph is self-complementary if it is isomorphic to its complement. For all self-complementary graphs on $$n$$ vertices, $$n$$ is

A cycle on $$n$$ vertices is isomorphic to its complement. The value of $$n$$ is __________.

Consider an undirectional graph $$G$$ where self-loops are not allowed. The vertex set of $$G$$ is $$\left\{ {\left( {i,j} \right):\,1 \le i \le 12,\,1 \le j \le 12} \right\}.$$ There is an edge between $$(a,b)$$ and $$(c,d)$$ if $$\left| {a - c} \right| \le 1$$ and $$\left| {b - d} \right| \le 1$$. The number of edges in this graph is _____.