#include <unordered_map>
#include <algorithm>
#include <iostream>

int main()
{
	std::unordered_map<char,unsigned int> count;
	std::string string = "hola caracola";

    for( char character : string )
		count[character]++;

	std::sort( std::begin( string ) , std::end( string ) ,
			   [&]( const char& lhs , const char& rhs )
	     	   {
			       return count[lhs] > count[rhs];
			   }
             );

	std::cout << string << std::endl;
}