// let's write a program that prints all words from a file having a specified
// length -- here we combine file input and interactive input.

import java.util.*;
import java.io.*;

public class FileIO2
{
  public static void main(String [] args) throws IOException
  {
    // Set up all our I/O.
    BufferedReader input = new BufferedReader(new FileReader("coleridge.txt"));
    BufferedReader kbd = new BufferedReader(new InputStreamReader(System.in));

    // Get input:  the length of words.
    System.out.print("What length of words would you like to see?  ");
    int desiredLength = Integer.parseInt(kbd.readLine());

    while(true)
    {
      String line = input.readLine();
      if (line == null)
        break;
      StringTokenizer tokenizer = new StringTokenizer (line, " .!,;");
      while (tokenizer.hasMoreTokens())
      {
        String word = tokenizer.nextToken();
        if (word.length() == desiredLength)
          System.out.println(word);
      }
    }
    input.close();
  }
}