Your imaginary friend is stuck between two powerful enemy groups! 

If he is to escape, he must act very fast and choose a road number that is not yet infested with ferocious enemies. Unfortunately, he cannot be sure about the enemy's current position. But you can do that from your imaginary-powerful-able-to-hack-all  computer.

 So it's time to help your (imaginary) friend escape from (imaginary) enemies with the help of your (imaginary) super computer.

Input Format

The only input line contains two integers 1 < M < N < 1000, representing 2 road numbers where the enemies are.

Output Format

Print any road number in-between the enemy roads, as they are considered safe.

Samples