So after one cycle, we amplify the number to two. Now this is only one cycle of PCR if two cycles take place. So let's suppose this is cycle number one. And now that we're in this position, we allow cycle number two to take place because now we have two DNA molecules and at one we begin with two. And so after two cycles, each one of these will be amplified to two. So we have two form from this, two form from this.