<p>Given an array of strings <code>strs</code>, return <em>the length of the <strong>longest uncommon subsequence</strong> between them</em>. If the longest uncommon subsequence does not exist, return <code>-1</code>.</p>

<p>An <strong>uncommon subsequence</strong> between an array of strings is a string that is a <strong>subsequence of one string but not the others</strong>.</p>

<p>A <strong>subsequence</strong> of a string <code>s</code> is a string that can be obtained after deleting any number of characters from <code>s</code>.</p>

<ul>
	<li>For example, <code>&quot;abc&quot;</code> is a subsequence of <code>&quot;aebdc&quot;</code> because you can delete the underlined characters in <code>&quot;a<u>e</u>b<u>d</u>c&quot;</code> to get <code>&quot;abc&quot;</code>. Other subsequences of <code>&quot;aebdc&quot;</code> include <code>&quot;aebdc&quot;</code>, <code>&quot;aeb&quot;</code>, and <code>&quot;&quot;</code> (empty string).</li>
</ul>

<p>&nbsp;</p>
<p><strong class="example">Example 1:</strong></p>
<pre><strong>Input:</strong> strs = ["aba","cdc","eae"]
<strong>Output:</strong> 3
</pre><p><strong class="example">Example 2:</strong></p>
<pre><strong>Input:</strong> strs = ["aaa","aaa","aa"]
<strong>Output:</strong> -1
</pre>
<p>&nbsp;</p>
<p><strong>Constraints:</strong></p>

<ul>
	<li><code>2 &lt;= strs.length &lt;= 50</code></li>
	<li><code>1 &lt;= strs[i].length &lt;= 10</code></li>
	<li><code>strs[i]</code> consists of lowercase English letters.</li>
</ul>

def LCS(word1, word2):
    n1 = len(word1)
    n2 = len(word2)
    L = [[0 for _ in range(n2+1)] for _ in range(n1+1)]

    for i in range(1, n1+1):
        for j in range(1, n2+1):
            if word1[i-1] == word2[j-1]:
                L[i][j] = L[i-1][j-1] + 1
            else:
                L[i][j] = max(L[i][j-1], L[i-1][j])
    return L[n1][n2]


class Solution:
    def findLUSlength(self, strs):
        strs = sorted(strs, key=lambda x: len(x), reverse=True)
        lcs = {}
        for i in range(len(strs)):
            k, x = -1, len(strs[i])
            for j in range(len(strs)):
                if i == j:
                    continue
                lcs[(i, j)] = l =lcs.get((i, j), LCS(strs[i], strs[j]))
                lcs[(j, i)] = l
                if l > k:
                    k = l
            if k != x:
                return x
        return -1
16800