 <span class="hljs-type">Number</span> = <span class="hljs-keyword">object</span>
      values: <span class="hljs-built_in">seq</span>[<span class="hljs-built_in">int</span>]
      lefts: <span class="hljs-built_in">seq</span>[<span class="hljs-built_in">seq</span>[<span class="hljs-built_in">bool</span>]] <span class="hljs-comment"># heights[i] is len of lefts[i]</span>

  <span class="hljs-keyword">func</span> parse(text: <span class="hljs-built_in">string</span>): <span class="hljs-type">Number</span> =
