// read a 2-D array from the user (the rows may have different 
// number of elements)
// Find the average of each row and the total average. 
import java.io.*;

public class TwoD {
    public static void main(String[] args) throws IOException {
	// set up the reading
	BufferedReader in = new BufferedReader(
			new InputStreamReader(System.in));
	// string for storing a line of input
	String line;

	// read the number of rows
	System.out.print("Please enter the number of rows: ");
	line = in.readLine();
	int rows = Integer.parseInt(line);

	// initialize the array:
	double [][] a = new double[rows][];

	for(int i = 0; i < rows; ++i) {
	    // read the number of elements in this row:
	    System.out.print("How many elements are in row " + i + " ? ");
	    line = in.readLine();
	    int elts = Integer.parseInt(line);

	    // create an array for the row:
	    a[i] = new double[elts];
	    
	    // read the elements
	    for (int j = 0; j < elts; ++j) {
		System.out.print("Please enter the element " + j + 
				 " of row  " + i + " : ");
		line = in.readLine();
		a[i][j] = Double.parseDouble(line);
	    }
	}

	// computing the averages:
	double sum = 0;
	int total_elts = 0;
	for (int i = 0; i < a.length; ++i) {
	    double sum_row = 0;
	    for (int j = 0; j < a[i].length; ++j) {
		sum += a[i][j];
		sum_row += a[i][j];
	    }
	    System.out.println("The average for row " + i + " is " +
			       sum_row/a[i].length);
	    total_elts += a[i].length;
	}
	System.out.println("The total average is " + sum/total_elts);
	
    }
}