#D11856. Array and Peaks
Array and Peaks
Array and Peaks
A sequence of n integers is called a permutation if it contains all integers from 1 to n exactly once.
Given two integers n and k, construct a permutation a of numbers from 1 to n which has exactly k peaks. An index i of an array a of size n is said to be a peak if 1 < i < n and a_i \gt a_{i-1} and a_i \gt a_{i+1}. If such permutation is not possible, then print -1.
Input
The first line contains an integer t (1 ≤ t ≤ 100) — the number of test cases.
Then t lines follow, each containing two space-separated integers n (1 ≤ n ≤ 100) and k (0 ≤ k ≤ n) — the length of an array and the required number of peaks.
Output
Output t lines. For each test case, if there is no permutation with given length and number of peaks, then print -1. Otherwise print a line containing n space-separated integers which forms a permutation of numbers from 1 to n and contains exactly k peaks.
If there are multiple answers, print any.
Example
Input
5 1 0 5 2 6 6 2 1 6 1
Output
1 2 4 1 5 3 -1 -1 1 3 6 5 4 2
Note
In the second test case of the example, we have array a = [2,4,1,5,3]. Here, indices i=2 and i=4 are the peaks of the array. This is because (a_{2} \gt a_{1} , a_{2} \gt a_{3}) and (a_{4} \gt a_{3}, a_{4} \gt a_{5}).
inputFormat
Input
The first line contains an integer t (1 ≤ t ≤ 100) — the number of test cases.
Then t lines follow, each containing two space-separated integers n (1 ≤ n ≤ 100) and k (0 ≤ k ≤ n) — the length of an array and the required number of peaks.
outputFormat
Output
Output t lines. For each test case, if there is no permutation with given length and number of peaks, then print -1. Otherwise print a line containing n space-separated integers which forms a permutation of numbers from 1 to n and contains exactly k peaks.
If there are multiple answers, print any.
Example
Input
5 1 0 5 2 6 6 2 1 6 1
Output
1 2 4 1 5 3 -1 -1 1 3 6 5 4 2
Note
In the second test case of the example, we have array a = [2,4,1,5,3]. Here, indices i=2 and i=4 are the peaks of the array. This is because (a_{2} \gt a_{1} , a_{2} \gt a_{3}) and (a_{4} \gt a_{3}, a_{4} \gt a_{5}).
样例
5
1 0
5 2
6 6
2 1
6 1
1
2 4 1 5 3
-1
-1
1 3 6 5 4 2
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