How to couple apin angular momenta of four electrons?

[humanist rho]

Homework Statement

How to couple spin angular momenta of four electrons?

2. The attempt at a solution
I've no idea.
I've learned coupling of two angular momenta and Clebsch Gordan coefficient.
But donno how to appy that to this system.

 

[diazona]

Just do them two at a time, like regular addition. E.g. first add the spins of two electrons, then of the other two, then add those two resulting states together.