CF296A Yaroslav and Permutations
Description
Yaroslav has an array that consists of $ n $ integers. In one second Yaroslav can swap two neighboring array elements. Now Yaroslav is wondering if he can obtain an array where any two neighboring elements would be distinct in a finite time.
Help Yaroslav.
Input Format
The first line contains integer $ n $ $ (1
Output Format
In the single line print "YES" (without the quotes) if Yaroslav can obtain the array he needs, and "NO" (without the quotes) otherwise.
Explanation/Hint
In the first sample the initial array fits well.
In the second sample Yaroslav can get array: $ 1 $ , $ 2 $ , $ 1 $ . He can swap the last and the second last elements to obtain it.
In the third sample Yarosav can't get the array he needs.