First steps with Feynman diagrams

[Rick16]

Homework Statement

Draw all the fourth-order (four vertex) diagrams for Compton scattering. (There are 17 of them; disconnected diagrams and "tadpoles"--photon lines terminating in an electron loop--don't count.)

Relevant Equations

no equations

This is problem 2.3 in Griffiths' Introducion to Elementary Particles. I have Griffiths' solutions, otherwise I would be completely lost. Nonetheless, I tried to come up with a solution of my own first. I found only one possibility, which looked ok to me, but it is not even among the 17 ones that Griffiths shows. Here is mine:

What is wrong with it?