You've got 2 prime numbers p and q.
The difference of p^2 - q^2 is also a prime number.
Can you now know for sure which prime number p and q is? Explain which possibilities there are for p and q, and why this are the only possibilities.
The only thing I could find was
p=3 and q=2
3^2 - 2^2 = 5 which is also a prime number.
But I dont know how to prove they are the only options (if they are).