explain it and write the proof, thanks !

6. Is it true that for any k, m > 3 integers there is a number R(k, m) such that if G is any graph on at least R(k, m) nodes then G contains a Kk subgraph or GC contains a Km subgraph? 6. Is it true that for any k, m > 3 integers there is a number R(k, m) such that if G is any graph on at least R(k, m) nodes then G contains a Kk subgraph or GC contains a Km subgraph