How do I solve this basic logic problem?

Question

If the police take you into custody, then if they inform you that you have the right to remain silent, then whatever you say will be used against you. If the police inform you that you have the right to remain silent, then if whatever you say will be used against you, then you should not say anything. Therefore, if the police take you into custody, then if they inform you that you have the right to remain silent, then you should not say anything. (P = The police take you into custody. I = The police inform you that you have the right to remain silent. W = Whatever you say will be used against you. S = You should say something.)

Answer 1

Are you trying to do a proof of this last statement?

If you are:

P → I

I → W

W → ~S

Therefore P → ~S