import java.io.*;
import java.util.*;
import java.text.*;
import java.math.*;
import java.util.regex.*;

public class Solution {
    public static int TARGET = 0;
    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();
            List<Integer> input = new ArrayList<>(len);
            for(int i=1; i<=len;i++){
                input.add(i);
            }
            // your code goes here
            TARGET=c;
            //System.out.println("RESULT->");
            List<Integer> res = lena_sort(input,c);
            if(TARGET<=0){
                    printArray(res);
            }else{
                System.out.println(-1);
            }
            //System.out.println("<-RESULT<"+TARGET);
        }
    }
    public static void printArray(List<Integer> a){
        for(int v: a){
            System.out.printf("%d ",v);
        }
        System.out.println();
    }
    public static List<Integer> lena_sort(List<Integer> nums, int target) {
        if (nums.size() <= 1||target<1) {
            return nums;
        }
        int pivot = nums.get(0);
        List<Integer> less = new ArrayList<>();
        List<Integer> more = new ArrayList<>();
        for (int i = 1; i < nums.size(); i++,target--,TARGET--) {
            // Comparison
            if (nums.get(i)<pivot) {
                less.add(nums.get(i));
            }
            else {
                more.add(nums.get(i));
            }
        }
        List<Integer> sorted_more = lena_sort(more,target);
        List<Integer> sorted_less = lena_sort(less,target);
        List<Integer> ans = new ArrayList<>();
        ans.addAll(sorted_more);
        ans.add(pivot);
        ans.addAll(sorted_less);
        return ans;
    }
}