This is a modification of my previous post here which has completely different meanings/solutions
$R = p_1p_2\cdots p_n + 1$ where $p_1 < p_2 < \cdots < p_n$ and $p$ are the first n prime numbers.
Prove that if $R$ is not prime then $R$ must have a prime factor $q$ that is larger than $p_n$.
I directly understand that this question refers to Euclid's primes proof however; I don't know really how to even tackle this problem. I am looking over euclid's proof and will hopefully run into a 'eureka' moment.
Any advice or tips on how to solve this problem would be very helpful and appreciated.