import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.io.IOException;
import java.util.StringTokenizer;

public class DoubleExerciseAnswer
{
    public static final int ROWS = 4;
    public static final int COLUMNS = 5;

    public static void main(String[] args) throws IOException
    {
        //Answer to Self-Test Question 21:
        BufferedReader keyboard = new BufferedReader(
                     new InputStreamReader(System.in));
        int[][] a = new int[ROWS][COLUMNS];
        String inputLine;

        System.out.println("Enter " + ROWS*COLUMNS +
                  " numbers, " + COLUMNS + " per line, on "
                          + ROWS + " lines:");
        int row, column;
        for (row = 0; row < ROWS; row++)
        {
            inputLine = keyboard.readLine();
            StringTokenizer numberList =
                                new StringTokenizer(inputLine);
            for (column = 0; column < COLUMNS; column++)
                a[row][column] =
                    Integer.parseInt(numberList.nextToken());
        }

        System.out.println("You entered:");
        echo(a);
    }

    //Answer to Self-Test Question 22:
    public static void echo(int[][] a)
    {
        int row, column;
        for (row = 0; row < a.length; row++)
        {
            for (column = 0; column < a[row].length; column++)
                System.out.print(a[row][column] + " ");
            System.out.println();
        }
    }
}