Palindrome Rearrangement

Given a string s of length n consisting only of lowercase English letters, determine if it is possible to rearrange the characters of s to form a palindrome.

A string is a palindrome if it reads the same forward and backward. According to the well-known condition of palindromic permutations, a string can be rearranged to form a palindrome if and only if at most one character appears an odd number of times.

For instance, if s = "aabb", a palindrome can be formed (e.g., "abba"). However, if s = "abcde", it is impossible to rearrange the characters to meet the palindrome condition, hence the answer would be NO.

Note: The problem only allows rearrangement of the characters (without removal or substitution), and the input integer n represents the length of the string.

inputFormat

The input consists of two lines:

1. The first line contains an integer n which is the length of the string.
2. The second line contains the string s consisting of only lowercase English letters.

outputFormat

Output a single line containing YES if the string can be rearranged to form a palindrome, or NO otherwise.

## sample

4
aabb

YES

</p>