set example

 #include  <set>
 using  namespace  std;
 int  main()  {
      set<int>  nums;
      int  val;
      while  (cin  >>  val)
                nums.insert(val);
      for  (set<int>::const_iterator  i  =
           nums.begin();  i  !=  nums.end();  ++i)
                cout  <<  *i  <<  endl;
 }