A. Diverse Permutation

time limit per test

1 second

memory limit per test

256 megabytes

input

standard input

output

standard output

Permutation p is an ordered set of integers p1,   p2,   ...,   pn, consisting of n distinct positive integers not larger than n. We'll denote as n the length of permutation p1,   p2,   ...,   pn.

Your task is to find such permutation p of length n, that the group of numbers |p1 - p2|, |p2 - p3|, ..., |pn - 1 - pn| has exactly kdistinct elements.

Input

The single line of the input contains two space-separated positive integers n, k (1 ≤ k < n ≤ 105).

Output

Print n integers forming the permutation. If there are multiple answers, print any of them.

Sample test(s)

input

3 2

output

1 3 2

input

3 1

output

1 2 3

input

5 2

output

1 3 2 4 5

Note

By |x| we denote the absolute value of number x.

解题说明：此题是要确保一列数中相邻两数的差的绝对值不同的次数不超过k，简单构造即可。

#include
#include
#include
#include
#include
#include
#include
using namespace std;

int a[100001];

int main()
{
    int n,k,i;
    scanf("%d %d",&n,&k);
    a[1]=1;
    for(i=2;k>=1;i++)
    {
        if(i%2==0)
        {
			a[i]=a[i-1]+k;
		}
		else
        {
			a[i]=a[i-1]-k;
		}
		k--;
    }
    for(i;i<=n;i++)
    {
		a[i]=i;
	}
	for(i=1;i<=n;i++)
    {
        printf("%d ",a[i]);
    }
	printf("\n");
    return 0;
}