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 PYTHON):

Solution:
temp = raw_input().split( " " )
k = int( temp[1] )
n = int( temp[0] )

set_size = 4

def gcd( a , b ):
    if a == 0:
        return b
    return gcd ( b % a , a )

nums = []
st = [k]
trial = k * 2

while len( nums ) != (set_size + 1 ) * n:
    
    while len( st ) != set_size:

        good = 0

        len_st = len( st )

        for i in xrange( len_st ):
            if gcd( st[ i ], trial ) == k:
                good += 1
            else:
                st[ i ] = trial
                break
                
            if good == len_st:
                st.append( trial )
        
        trial += k
            
    nums.extend( st )
    nums.append('\n')
    st = [trial]

print trial - k
for elt in nums:
    print elt,

    


##sets = []
##st = [k]
##
##i = 2 * k
##
##for i in xrange( n ):
##
##    len_s = len( st )
##
##    while len( st ) != 4:
##
##        for s in st:
##            good = 0
##            if gcd( i , s ) == k:
##                good += k
##
##        if good == len_s:
##            s.append( i )
##
##        i += k
##    sets.append(st)
##    st = [i]