
#include <iostream>#include <string>using namespace std;int main(){string str;while(cin>>str){int Char_array[127] = {0};int max = 0;for(int i = 0;i<str.size();i++){Char_array[str[i]]++;if(Char_array[str[i]]>max)max = Char_array[str[i]];}while(max){//从0检索就自带Ascii表顺序在里面for(int i = 0;i<127;i++)if(Char_array[i]==max)cout<<(char)i;max--;}cout<<endl;}}
