Using N#C[Cu], CSc1ncc2c(N)c(Br)c(=O)n(C3CCC3)c2n1 to produce CSc1ncc2c(N)c(C#N)c(=O)n(C3CCC3)c2n1, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.