How many cup of coffee you consume in a day?

I think coffee is delicious, I drink a cup of coffee every mornig, and sometimes a second cup during the day. If I start to drink more than one coffee a day, after few days I don't feel awaking power of this drink. Than I try to not drink it at all (I drink green tea instead) for about 1 week, and it helps:) So I can start drinking my morning cup of coffee untill I drink it too much again.