sleeping

I often think I hope to sleep 30 minutes like 6 hours. If I needed time, I took not sleeping. therefore I want to do that. I heard drinking coffee before 30 minute sleeping, I could get awaking. I have done that. I think that is not true. I think sleeping is inporetant. I heard Einstein sleep 12 hours , Edison sleep 1 hour everyday, probably. therefore I think each parson have best time.