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 CPP):

Solution:
#include <bits/stdc++.h>
using namespace std;
int maxn, a[1000001][4], sum = 2;
int gcd(int x, int y) {
  if (y == 0) return x;
  return gcd(y, x % y);
}
int main() {
  int n, k;
  cin >> n >> k;
  for (int i = 1; i <= n; ++i) {
    a[i][0] = (6 * i - 5);
    a[i][1] = (6 * i - 3);
    a[i][2] = (6 * i - 1);
    while (gcd(sum, a[i][0]) != 1 || gcd(sum, a[i][1]) != 1 ||
           gcd(sum, a[i][2]) != 1)
      sum += 2;
    a[i][3] = sum;
    sum += 2;
    maxn = max(maxn, a[i][2]);
    maxn = max(maxn, a[i][3]);
  }
  cout << maxn * k << endl;
  for (int i = 1; i <= n; ++i)
    cout << a[i][0] * k << ' ' << a[i][1] * k << ' ' << a[i][2] * k << ' '
         << a[i][3] * k << endl;
  return 0;
}