Staying awake during my first two cles?

Due to my screwed-up circadian rhythm, I tend to only sleep a few hours a night, and some nights, I don't sleep at all. During my first two cles, which are in the morning, I feel unbearably sleepy. After lunch though, I start to perk up and I can usually go until a little later that night, then sleep, which puts my rhythm back in order (temporarily, anyway). Anyway, how can I stay awake during those cles???