<p>You are given an array of strings <code>words</code>. Each element of <code>words</code> consists of <strong>two</strong> lowercase English letters.</p>

<p>Create the <strong>longest possible palindrome</strong> by selecting some elements from <code>words</code> and concatenating them in <strong>any order</strong>. Each element can be selected <strong>at most once</strong>.</p>

<p>Return <em>the <strong>length</strong> of the longest palindrome that you can create</em>. If it is impossible to create any palindrome, return <code>0</code>.</p>

<p>A <strong>palindrome</strong> is a string that reads the same forward and backward.</p>

<p>&nbsp;</p>
<p><strong class="example">Example 1:</strong></p>

<pre>
<strong>Input:</strong> words = [&quot;lc&quot;,&quot;cl&quot;,&quot;gg&quot;]
<strong>Output:</strong> 6
<strong>Explanation:</strong> One longest palindrome is &quot;lc&quot; + &quot;gg&quot; + &quot;cl&quot; = &quot;lcggcl&quot;, of length 6.
Note that &quot;clgglc&quot; is another longest palindrome that can be created.
</pre>

<p><strong class="example">Example 2:</strong></p>

<pre>
<strong>Input:</strong> words = [&quot;ab&quot;,&quot;ty&quot;,&quot;yt&quot;,&quot;lc&quot;,&quot;cl&quot;,&quot;ab&quot;]
<strong>Output:</strong> 8
<strong>Explanation:</strong> One longest palindrome is &quot;ty&quot; + &quot;lc&quot; + &quot;cl&quot; + &quot;yt&quot; = &quot;tylcclyt&quot;, of length 8.
Note that &quot;lcyttycl&quot; is another longest palindrome that can be created.
</pre>

<p><strong class="example">Example 3:</strong></p>

<pre>
<strong>Input:</strong> words = [&quot;cc&quot;,&quot;ll&quot;,&quot;xx&quot;]
<strong>Output:</strong> 2
<strong>Explanation:</strong> One longest palindrome is &quot;cc&quot;, of length 2.
Note that &quot;ll&quot; is another longest palindrome that can be created, and so is &quot;xx&quot;.
</pre>

<p>&nbsp;</p>
<p><strong>Constraints:</strong></p>

<ul>
	<li><code>1 &lt;= words.length &lt;= 10<sup>5</sup></code></li>
	<li><code>words[i].length == 2</code></li>
	<li><code>words[i]</code> consists of lowercase English letters.</li>
</ul>

class Solution:
    def longestPalindrome(self, words: List[str]) -> int:
        length = 0
        flag = 0
        mp = {}
        
        # Count occurrences of each word
        for word in words:
            mp[word] = mp.get(word, 0) + 1

        # Function to reverse a two-letter word
        def reverse_word(word):
            return word[1] + word[0]

        # Iterate through the words list
        for i in range(len(words)):
            if words[i][0] != words[i][1]:  # Case where the two characters are different
                rev_w = reverse_word(words[i])

                if rev_w in mp and mp[rev_w] > 0:
                    count = min(mp[words[i]], mp[rev_w])
                    length += count * 4

                    # Remove the word and its reverse from the map
                    mp[words[i]] = 0
                    mp[rev_w] = 0

            else:  # Case where both characters are the same (palindromic word)
                count = mp[words[i]]
                if count % 2 == 0:
                    length += count * 2
                else:
                    if flag == 0:  # First odd-count palindrome word
                        length += count * 2
                        flag = 1
                    else:
                        length += (count - 1) * 2
                mp[words[i]] = 0  # Set the count to 0 after processing

        return length

1173