In a house, there are rooms in a line, with the rooms being numbered from to from the left to the right. In each room, there are two doors, allowing someone to move from his current room to the room to his left or to the room his right. Two exceptions to this are the rooms numbered and , which only have doors to their right and left respectively since there’s no room to the left of room , and no room to the right of room .
In the house, there is a cat named Tom, and a mouse named Jerry. Tom is initially at room , while Jerry is initially at room . However, Tom does not know where Jerry is, and Jerry does not know where Tom is. As usual, Tom wants to catch Jerry. At each minute, he uses one of the doors to move to another room. Jerry also keeps moving from one room to another. However, instead of using the doors, Jerry has dug small underground tunnels that allow him to move between consecutive rooms without being noticed.
The following figure shows the layout of the house when there are rooms.
It is guaranteed that during each minute, both Tom and Jerry will always move to an adjacent room and will never stay in the same room for more than one minute. The only way for Tom to catch Jerry is if they both find themselves in the same room at the exact same time. Both of them will run blindly, that is, unless they are at the same room, neither will no where the other one is.
Given the values of and , find out if there is any chance that Tom will catch Jerry.
The input consists of a single line containing three integers - , and , denoting the total number of rooms and the rooms in which Tom and Jerry are initially.
If there is any chance that Tom will catch Jerry, output “YES” (without the quotes). Otherwise, output “NO” (without the quotes).
4 3 3
Since Tom and Jerry are both in the same room initially, Tom will catch Jerry right away.
5 2 4
In minute 1, Tom is in room 2 and Jerry is in room 4. If Tom moves to the right and Jerry moves to the left in the next minute, they will both move to room 3, where Tom will capture Jerry.