import java.io.*; import java.util.*; import java.text.*; import java.math.*; import java.util.regex.*; public class Solution { static int kol ; public ArrayList lena_sort(ArrayList nums) { if (nums.size() <= 1) { return nums; } int pivot = nums.get(0); ArrayList less=new ArrayList<>() ; ArrayList more=new ArrayList<>() ; for (int i = 1; i < nums.size(); ++i) { kol++; if (nums.get(i) < pivot) { less.add(nums.get(i)); } else { more.add(nums.get(i)); } } ArrayList sorted_less = lena_sort(less); ArrayList sorted_more = lena_sort(more); ArrayListans = new ArrayList<>(); for(Integer j : sorted_less){ ans.add(j); } ans.add(pivot); for(Integer j : sorted_more){ ans.add(j); } return ans; } public static void main(String[] args) { Scanner in = new Scanner(System.in); int q = in.nextInt(); for(int a0 = 0; a0 < q; a0++){ int len = in.nextInt(); int c = in.nextInt(); if(clen*(len-1)/2) System.out.println(-1); else{ ArrayList arr = new ArrayList<>(); for(int i = 1; i<=len ;i++) arr.add(i); Collections.shuffle(arr); Solution s = new Solution(); Solution.kol=0; ArrayList ans = s.lena_sort(arr); for(Integer i : arr) System.out.print(i+" "); System.out.println(); //System.out.println(kol); } } } }