Consider two following problems:P roblem$1$Instance: An undirected graph G $=($V$,$ E$)$ and an integer number k$.$Question: Is there a function : V $\{0,...,$ k $1\},$ such that$($u$)6=($v$),$ whenever $\{$u$,$ v$\}$ E$?$P roblem$2$Instance: An undirected graph G $=($V$,$ E$)$ and an integer number k$.$Question: Are there at most k cliques is G$,$ whose union is V $?$Prove: P roblem$1$ P P roblem$2.$