**Cuperman** has two cups **A** and **B**. There are **x **balls in **A**, **y** balls in **B. **You can move balls between these two cups. The number of balls can be moved from **A** to B (or from B to A) is equal to the number of balls in **B **(or in **A**). For example, if A has 3 balls and B has 2 balls, you only can move 2 balls from A to B, but cannot move 2 balls from B to A. Now **Cuperman **wants to know, how many move steps he need to obtain one empty cup.