Activity Navigation Logic
<p>I have 3 Activities...the first Activity have a button that start third Activity. 
The problem is:
   When I am in 3 - rd activity press "back" button its navigate me back to 1 - st Activity, but i need to 2 - nd one. My stack of Activities always should look like : 
1. first Activity
2. second Activity
3. third Activity</p>

<p>How to do that ? Thanks...</p>
