Problem 6.309

Which of the following processes are forbidden by the Iaw of conservation of strangeness: (1) $\pi^{-}+p \rightarrow \Sigma-+K^{+}$ (2) $\pi^{-}+p \rightarrow \Sigma++K$ (3) $\pi^{-}+p \rightarrow K^{+}+K^{-}+n$ (4) $n+p \rightarrow \Lambda^{0}+\Sigma^{+}$ (5) $\pi^{-}+n \rightarrow \Xi^{-}+K^{+}+K^{-}$ (6) $K^{-}+p \rightarrow \Omega^{-}+K^{+}+K^{0} ?$