import java.io.BufferedReader;import java.io.InputStreamReader;import java.io.FileInputStream; import java.io.BufferedWriter;import java.io.OutputStreamWriter;import java.io.FileOutputStream; import java.io.FileReader;import java.io.FileWriter;import java.io.IOException;import java.util.ArrayList; public class Youtube{/** * Keeps track of whether the first reading has been performed. */protected..