Question 10
(NET 2) IMO3. Let $n$ be an integer greater than $2$. Define $V=\{1+kn\mid k=1,2,\ldots\}$. A number $p\in V$ is called indecomposable in $V$ if it is not possible to find numbers $q_1,q_2\in V$ such that $q_1q_2=p$. Prove that there exists a number $N\in V$ that can be factorized into indecomposable factors in $V$ in more than one way.