Graph Algorithms · Easy problem

A network connects sites $k,l,m,n,o$ with possible cables and costs $kl{:}2, km{:}4, lm{:}3, ln{:}6, mn{:}1, mo{:}5, no{:}2$. Running Kruskal's algorithm on all $7$ possible cables, how many of them are rejected because they would close a cycle?