package com.word;
import java.io.*;
import java.util.*;

public class Unique {
    public static void main (String[] args) {
        BufferedReader br = null;
        HashSet<String> words = new HashSet<>();
        StringTokenizer st;
        File[] list = new File ("//Users//Documents//Java//1//set").listFiles(new FNFilter("java"));

        try {
            for (int i = 0; i < list.length; i++){
                br = new BufferedReader(new FileReader(list[i]));
                st = new StringTokenizer(list, " \t\n\r,.");  
                while (st.hasMoreTokens()){
                    words.add(br.nextToken());
                }
            }

        } catch (Exception e){
            e.printStackTrace();
        } finally {
            try {
                if (br != null){
                    br.close();
                }
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
        System.out.println(words.size());
        for (File W : list) {
            System.out.println(W);
        }
    }
}