human
I found an interesting problem on https://leetcode.com/problems/longest-palindrome/:
Given a string which consists of lowercase or uppercase letters, find the length of the longest palindromes that can be built with those letters.

This is case sensitive, for example "Aa" is not considered a palindrome here.

Note:
Assume the length of given string will not exceed 1,010.

Example: 

Input:
"abccccdd"

Output:
7

Explanation:
One longest palindrome that can be built is "dccaccd", whose length is 7.

I tried it in Python, but could not do it. Can you solve it?

Can you provide a Python code to find the length of the longest palindromes that can be built with those letters?
assistant
#Here is Python code to find the length of the longest palindromes that can be built with those letters.

class Solution:
     def longestPalindrome(self, s):
 
         l = list(s)
         result = 0
 
         for x in set(s):
             x_count = l.count(x)
             if x_count % 2 == 0:
                 result += x_count
             else:
                 result += x_count-1
 
         if len(l) > result:
             result += 1
 
         return result