wordlist results

(Wrong Answer:, see below for the correct answer too)
Problem: WORDLIST
State: Wrong Answer
Total score for this submission: 0
Your code compiled successfully but produced the following warnings

Test Case #0 for 2 points
Wrong Answer
Runtime: 0.152
Test Case #1 for 2 points
Wrong Answer
Runtime: 0.176
Test Case #2 for 2 points
Wrong Answer
Runtime: 0.232
Test Case #3 for 2 points
Wrong Answer
Runtime: 0.224
Test Case #4 for 2 points
Wrong Answer
Runtime: 0.572
Test Case #5 for 2 points
Wrong Answer
Runtime: 0.56
Test Case #6 for 2 points
Wrong Answer
Runtime: 0.492
Test Case #7 for 2 points
Wrong Answer
Runtime: 1.1
Test Case #8 for 2 points
Wrong Answer
Runtime: 1.152
Test Case #9 for 2 points
Wrong Answer
Runtime: 1.724

import java.util.ArrayList;
import java.util.Collections;
import java.util.Scanner;

/**
 * Created by aditya on 14-10-2014.
 */
public class Main {

    public static void main(String args[]) {

        Scanner scan = new Scanner(System.in);
        int n = Integer.parseInt(scan.nextLine());
        ArrayList<String> lines = new ArrayList<String>();
        ArrayList<String> words = new ArrayList<String>();
        boolean once_entered = true;
        for (int i = 0; i < n; i++) {
            lines.add(i, scan.nextLine() + " ");
        }
        for (int i = 0; i < n; i++) {
            String word = "";
            for (int j = 0; j < lines.get(i).length(); j++) {
                char char_0 = lines.get(i).toLowerCase().charAt(j);
                if ((int) (char_0) >= (int) ('a') && (int) (char_0) <= (int) ('z')) {
                    word += char_0;
                    once_entered = false;
                } else if (!once_entered) {
                    words.add(word);
                    word = "";
                    once_entered = true;
                }
            }
        }
        for (int i = 0; i < words.size(); i++) {
            for (int j = 0; j < words.size(); j++) {
                if (i == j) continue;
                else if (words.get(i).equals(words.get(j))) {
                    words.remove(words.get(j));
                }
            }
        }
        Collections.sort(words);
        System.out.println(words.size());
        for (int i = 0; i < words.size(); i++) {
            System.out.println(words.get(i));
        }
    }
}

(Correct Answer:)
Problem: WORDLIST
State: Accepted
Total score for this submission: 20
Test Case #0 for 2 points
Correct Answer
Runtime: 0.156
Test Case #1 for 2 points
Correct Answer
Runtime: 0.16
Test Case #2 for 2 points
Correct Answer
Runtime: 0.212
Test Case #3 for 2 points
Correct Answer
Runtime: 0.204
Test Case #4 for 2 points
Correct Answer
Runtime: 0.524
Test Case #5 for 2 points
Correct Answer
Runtime: 0.444
Test Case #6 for 2 points
Correct Answer
Runtime: 0.456
Test Case #7 for 2 points
Correct Answer
Runtime: 1.096
Test Case #8 for 2 points
Correct Answer
Runtime: 1.54
Test Case #9 for 2 points
Correct Answer
Runtime: 1.636

import java.util.ArrayList;
import java.util.Collections;
import java.util.Scanner;

/**
 * Created by aditya on 14-10-2014.
 */
public class Main {

    public static void main(String args[]) {

        Scanner scan = new Scanner(System.in);
        int n = Integer.parseInt(scan.nextLine());
        ArrayList<String> lines = new ArrayList<String>();
        ArrayList<String> words = new ArrayList<String>();
        ArrayList<String> words_2 = new ArrayList<String>();
        boolean once_entered = true;
        for (int i = 0; i < n; i++) {
            lines.add(i, scan.nextLine() + " ");
        }
        for (int i = 0; i < n; i++) {
            String word = "";
            for (int j = 0; j < lines.get(i).length(); j++) {
                char char_0 = lines.get(i).toLowerCase().charAt(j);
                if ( (char_0) >=  ('a') &&  (char_0) <=  ('z')) {
                    word += char_0;
                    once_entered = false;
                } else if (!once_entered) {
                    words.add(word);
                    word = "";
                    once_entered = true;
                }
            }
        }
        for (int i = 0; i < words.size(); i++) {
            boolean contains =false;
            for(int j=0;j<words_2.size();j++){
                if(words_2.get(j).contentEquals(words.get(i)))
                    contains=true;
            }
            if(!contains)
                words_2.add(words.get(i));
        }
        Collections.sort(words_2);
        System.out.println(words_2.size());
        for (int i = 0; i < words_2.size(); i++) {
            System.out.println(words_2.get(i));
        }
    }
}