A clique in an undirected graph G$($V$,$ E$)$ is a subset V $$ V $,$ such that each

pair of node $($v$1,$ v$2)$ where v$1$ in V $,$ v$2$ in V $$ and v$16=$ v$2,$ has an edge between them,

i$.$e$.,($v$1,$ v$2)$ in E$.$ The size of the clique is the number of nodes it contains.