小慕在开发一个文本处理工具时遇到了一个需求：需要删除字符串`s`中，如果有多个字符的出现次数相同且都是最少，则将这些字符全部删除。
提示：带虚线的词点一下有通俗解释。
输入描述
输入只包含小写字母
输出描述
<div data-page-id="TyJVdXrDSoN91wxPr7VcMRhtnHd" data-docx-has-block-data="false"> <div style="white-space-collapse:preserve;" class="ace-line ace-line old-record-id-WaMIdmcAuoGICoxozJ4c6dX7nUd"> 输出删除后剩余的字符串；若删除后字符串长度为<code>0</code>，则输出字符串<code>"empty"</code> </div> </div> <span data-lark-record-data="{"rootId":"TyJVdXrDSoN91wxPr7VcMRhtnHd","text":{"initialAttributedTexts":{"text":{"0":"输出删除后剩余的字符串；若删除后字符串长度为0，则输出字符串\"empty\""},"attribs":{"0":"*0+m*0*1+1*0+7*0*1+7"}},"apool":{"numToAttrib":{"0":["author","7115054903550050305"],"1":["inlineCode","true"]},"nextNum":2}},"type":"text","referenceRecordMap":{},"extra":{"mention_page_title":{},"external_mention_url":{}},"isKeepQuoteContainer":false,"isFromCode":false,"selection":[{"id":8,"type":"text","selection":{"start":0,"end":37},"recordId":"WaMIdmcAuoGICoxozJ4c6dX7nUd"}],"payloadMap":{},"isCut":false}" data-lark-record-format="docx/text" class="lark-record-clipboard"></span>
示例
示例 1
输入
abcdd
输出
dd
时间限制 1000 ms · 内存限制 128 MB