- Time limit: 1.00 s
- Memory limit: 512 MB
A famous NP-complete problem is to detect if a graph can be colored using at most colors. In a valid coloring, each node is given a color and each edge connects two nodes with different colors.
In this problem, your task is to find out if a cycle graph of nodes can be colored using at most colors. A cycle graph consists of a single cycle.
Input
The only input line has two integers and .
Output
Print "YES", if the graph can be colored, and "NO" otherwise.
Constraints
Example
Input:
5 3
Output:
YES