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 DEBUG = 1;
set<int> Free;
set<int> add;
set<int> Del;
int Ls = 1;
set<int>::iterator frpos;
int gen_next() {
  if (frpos == Free.end()) {
    add.insert(Ls);
    return Ls++;
  }
  return *(frpos++);
}
void mdel(int x) { Del.insert(x); }
void fuckoff() {
  for (set<int>::iterator it = add.begin(); it != add.end(); it++)
    Free.insert(*it);
  add.clear();
  for (set<int>::iterator it = Del.begin(); it != Del.end(); it++)
    Free.erase(*it);
  frpos = Free.begin();
}
void fuck_off(int n) {
  for (set<int>::iterator it = add.begin(); it != add.end(); it++)
    Free.insert(*it);
  for (set<int>::iterator it = Free.begin(); it != Free.end(); it++)
    if ((*it) % n == 0) Del.insert((*it));
  add.clear();
  for (set<int>::iterator it = Del.begin(); it != Del.end(); it++)
    Free.erase(*it);
  frpos = Free.begin();
}
int gcd(int a, int b) {
  int c;
  while (b != 0) {
    c = a % b;
    a = b;
    b = c;
  }
  return a;
}
int main() {
  int n;
  long long k;
  cin >> n >> k;
  frpos = Free.begin();
  vector<vector<int> > ans;
  int num = 1;
  for (int i = 0; i < (int)n; i++) {
    num = num + 6;
  }
  num -= 6;
  cout << (num + 4) * k << endl;
  num = 1;
  for (int i = 0; i < (int)n; i++) {
    cout << (num)*k << " " << (num + 1) * k << " " << (num + 2) * k << " "
         << (num + 4) * k;
    cout << endl;
    num = num + 6;
  }
  return 0;
}