The integers $a$, $b$, $c$ and $d$ are such that $a$ and $b$ are relatively prime, $d\leq 2022$ and $a+b+c+d = ac + bd = 0$. Determine the largest possible value of $d$,
Problem
Source: Bulgaria JBMO TST 2022 Day 2 Problem 3
Tags: number theory, coprime, Divisibility, relatively prime