Problem: Dreamoon likes to play with sets, integers and <image>. <image> is defined as the largest positive integer that divides both a and b.

Let S be a set of exactly four distinct integers greater than 0. Define S to be of rank k if and only if for all pairs of distinct elements si, sj from S, <image>.

Given k and n, Dreamoon wants to make up n sets of rank k using integers from 1 to m such that no integer is used in two different sets (of course you can leave some integers without use). Calculate the minimum m that makes it possible and print one possible solution.

Input

The single line of the input contains two space separated integers n, k (1 ≤ n ≤ 10 000, 1 ≤ k ≤ 100).

Output

On the first line print a single integer — the minimal possible m. 

On each of the next n lines print four space separated integers representing the i-th set.

Neither the order of the sets nor the order of integers within a set is important. If there are multiple possible solutions with minimal m, print any one of them.

Examples

Input

1 1


Output

5
1 2 3 5


Input

2 2


Output

22
2 4 6 22
14 18 10 16

Note

For the first example it's easy to see that set {1, 2, 3, 4} isn't a valid set of rank 1 since <image>.

Solution (in JAVA):

Solution:
import java.util.Scanner;
/**
 * 
 */

/**
 * @author �
 *
 */
public final class b2 {

    /**
     * @param args
     */
    public static void main(String[] args) {
        Scanner datain = new Scanner(System.in);
        long a = datain.nextInt();
        long b = datain.nextInt();
        
        System.out.println(b*(6*(a-1)+5));
    for(int i=0;i<a;i++){System.out.println(""+b*(6*i+1)+" "+b*(6*i+3)+" "+b*(6*i+4)+" "+b*(6*i+5));}
//      PrintWriter dataout = new PrintWriter(System.out);
//      dataout.close();

    }

}