#include <iostream>
#include <cassert>
#include <list>
#include <string>
#include <set>
using namespace std;
int main()
{
string s("There is no distinctly native American criminal class");
list<char> list1(s.begin(), s.end());
// Put the characters in list1 into set1:
set<char> set1;
list<char>::iterator i;
for (i = list1.begin(); i != list1.end(); ++i)
set1.insert(*i);
set<char>::iterator j;
for (j = set1.begin(); j != set1.end(); ++j)
cout << *j;
return 0;
}