</div></div></div></div></div><div class="row"><div class="column"><h4 class="ui top attached block header">输出格式</h4><div class="ui bottom attached segment font-content"><div style="position: relative; overflow: hidden;"><div class=content><div>&nbsp;</div>
<div><span style="font-size: medium">&nbsp;&nbsp;&nbsp;&nbsp;一个整数，表示排队的方法数．</span></div></div></div></div></div></div><div class="row"><div class="column"><h4 class="ui top attached block header">样例</h4><div class