Problem

Source: 2017 Korea Winter Program Practice Test 2 #1

Tags: number theory



For every positive integers $n,m$, show that there exist two sets $A,B$ which satisfy the following. $A$ is a set of $n$ successive positive integers, and $B$ is a set of $m$ successive positive integers. $A\cup B = \phi$ For every $a\in A$ and $b\in B$, $a$ and $b$ are not relatively prime.