<p>Two strings <code>word1</code> and <code>word2</code> are considered <strong>almost equivalent</strong> if the differences between the frequencies of each letter from <code>'a'</code> to <code>'z'</code> between <code>word1</code> and <code>word2</code> is <strong>at most</strong> <code>3</code>.</p> <p>Given two strings <code>word1</code> and <code>word2</code>, each of length <code>n</code>, return <code>true</code> <em>if </em><code>word1</code> <em>and</em> <code>word2</code> <em>are <strong>almost equivalent</strong>, or</em> <code>false</code> <em>otherwise</em>.</p> <p>The <strong>frequency</strong> of a letter <code>x</code> is the number of times it occurs in the string.</p> <p> </p> <p><strong class="example">Example 1:</strong></p> <pre> <strong>Input:</strong> word1 = "aaaa", word2 = "bccb" <strong>Output:</strong> false <strong>Explanation:</strong> There are 4 'a's in "aaaa" but 0 'a's in "bccb". The difference is 4, which is more than the allowed 3. </pre> <p><strong class="example">Example 2:</strong></p> <pre> <strong>Input:</strong> word1 = "abcdeef", word2 = "abaaacc" <strong>Output:</strong> true <strong>Explanation:</strong> The differences between the frequencies of each letter in word1 and word2 are at most 3: - 'a' appears 1 time in word1 and 4 times in word2. The difference is 3. - 'b' appears 1 time in word1 and 1 time in word2. The difference is 0. - 'c' appears 1 time in word1 and 2 times in word2. The difference is 1. - 'd' appears 1 time in word1 and 0 times in word2. The difference is 1. - 'e' appears 2 times in word1 and 0 times in word2. The difference is 2. - 'f' appears 1 time in word1 and 0 times in word2. The difference is 1. </pre> <p><strong class="example">Example 3:</strong></p> <pre> <strong>Input:</strong> word1 = "cccddabba", word2 = "babababab" <strong>Output:</strong> true <strong>Explanation:</strong> The differences between the frequencies of each letter in word1 and word2 are at most 3: - 'a' appears 2 times in word1 and 4 times in word2. The difference is 2. - 'b' appears 2 times in word1 and 5 times in word2. The difference is 3. - 'c' appears 3 times in word1 and 0 times in word2. The difference is 3. - 'd' appears 2 times in word1 and 0 times in word2. The difference is 2. </pre> <p> </p> <p><strong>Constraints:</strong></p> <ul> <li><code>n == word1.length == word2.length</code></li> <li><code>1 <= n <= 100</code></li> <li><code>word1</code> and <code>word2</code> consist only of lowercase English letters.</li> </ul>