#include <iostream>
#include <fstream>
#include <string>
#include <algorithm>
#include <iterator>
#include <unordered_set>
using namespace std;

int main()
{
	ifstream in("file.txt");
	unordered_set<string> words;
	copy (istream_iterator<string>(in), istream_iterator<string>(), 
		inserter(words, words.begin()));
	copy (words.begin(), words.end(), 
		ostream_iterator<string>(cout, "\n"));
}