#include <algorithm>
#include <iostream>
#include <iterator>
#include <string>

int main()
{
  std::string s = "Hallo, Welt";
  std::string u;
  std::cout << s << '\n';
  std::sort(begin(s), end(s));

  std::unique_copy(begin(s), end(s), std::back_inserter(u));

  std::cout << u << '\n';
}