Problem #PRU-98187

Problems Set theory and logic Theory of algotithms

Problem

Initially, a natural number \(A\) is written on a board. You are allowed to add to it one of its divisors, distinct from itself and one. With the resulting number you are permitted to perform a similar operation, and so on.

Prove that from the number \(A = 4\) one can, with the help of such operations, come to any given in advance composite number.