<p>You are given two strings <code>word1</code> and <code>word2</code>. You want to construct a string <code>merge</code> in the following way: while either <code>word1</code> or <code>word2</code> are non-empty, choose <strong>one</strong> of the following options:</p>
<ul>
<li>If <code>word1</code> is non-empty, append the <strong>first</strong> character in <code>word1</code> to <code>merge</code> and delete it from <code>word1</code>.
<ul>
<li>For example, if <code>word1 = "abc"</code>and <code>merge = "dv"</code>, then after choosing this operation, <code>word1 = "bc"</code> and <code>merge = "dva"</code>.</li>
</ul>
</li>
<li>If <code>word2</code> is non-empty, append the <strong>first</strong> character in <code>word2</code> to <code>merge</code> and delete it from <code>word2</code>.
<ul>
<li>For example, if <code>word2 = "abc"</code>and <code>merge = ""</code>, then after choosing this operation, <code>word2 = "bc"</code> and <code>merge = "a"</code>.</li>
</ul>
</li>
</ul>
<p>Return <em>the lexicographically <strong>largest</strong></em><code>merge</code><em> you can construct</em>.</p>
<p>A string <code>a</code> is lexicographically larger than a string <code>b</code> (of the same length) if in the first position where <code>a</code> and <code>b</code> differ, <code>a</code> has a character strictly larger than the corresponding character in <code>b</code>. For example, <code>"abcd"</code> is lexicographically larger than <code>"abcc"</code> because the first position they differ is at the fourth character, and <code>d</code> is greater than <code>c</code>.</p>
