A permutation $*p*$ is an ordered group of numbers $*p*_{1},   *p*_{2},   ...,   *p*_{*n*}$, consisting of $*n*$ distinct positive integers, each is no more than $*n*$. We'll define number $*n*$ as the length of permutation $*p*_{1},   *p*_{2},   ...,   *p*_{*n*}$.

Simon has a positive integer $*n*$ and a non-negative integer $*k*$, such that $2*k* ≤ *n*$. Help him find permutation $*a*$ of length $2*n*$, such that it meets this equation: .

Input

The first line contains two integers $*n*$ and $*k*$ ($1 ≤ *n* ≤ 50000$, $0 ≤ 2*k* ≤ *n*$).

Output

Print $2*n*$ integers $*a*_{1}, *a*_{2}, ..., *a*_{2*n*}$ — the required permutation $*a*$. It is guaranteed that the solution exists. If there are multiple solutions, you can print any of them.

Note

Record $|*x*|$ represents the absolute value of number $*x*$.

In the first sample $|1 - 2| - |1 - 2| = 0$.

In the second sample $|3 - 2| + |1 - 4| - |3 - 2 + 1 - 4| = 1 + 3 - 2 = 2$.

In the third sample $|2 - 7| + |4 - 6| + |1 - 3| + |5 - 8| - |2 - 7 + 4 - 6 + 1 - 3 + 5 - 8| = 12 - 12 = 0$.