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>
#pragma comment(linker, "/STACK:1024000000,1024000000")
using namespace std;
const int maxn = 1000000;
int ans[maxn][6];
int main() {
  int n, k;
  scanf("%d%d", &n, &k);
  int m = 0;
  int cur = 0;
  for (int i = 1;; i++) {
    if (i % 2) {
      m = i + 4;
      ans[++cur][1] = i;
      ans[cur][2] = i + 1;
      ans[cur][3] = i + 2;
      ans[cur][4] = i + 4;
      i = i + 5;
    } else {
      i++;
    }
    if (cur == n) break;
  }
  printf("%d\n", m * k);
  for (int i = 1; i <= n; i++) {
    for (int j = 1; j <= 4; j++) {
      printf("%d", ans[i][j] * k);
      if (j != 4) cout << ' ';
    }
    cout << endl;
  }
}