using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
class Solution
{
    static void LenaSortComparisons(int len, int c)
    {
        int maxComparisons = (len - 1) * len / 2;
        if(maxComparisons < c)
        {
            Console.WriteLine(-1);
            return;
        }        
        // e.g. len = 4 --> start = { 1, 2, 3, 4 }
        //      which takes 3+2+1=6 comparisons to sort.
        int[] arr = Enumerable.Range(1, len).ToArray();   
        for(int piv = maxComparisons - c, k = 0; piv < len && piv != 0; ++k, ++piv)
        {
            int temp = arr[k];
            arr[k] = arr[piv - 1];
            arr[piv - 1] = temp;            
        }        
        Console.WriteLine(string.Join(" ", arr));
    }
    
    static void Main(String[] args)
    {
        int q = Convert.ToInt32(Console.ReadLine());
        for(int a0 = 0; a0 < q; a0++)
        {
            string[] tokens_len = Console.ReadLine().Split(' ');
            int len = Convert.ToInt32(tokens_len[0]);
            int c = Convert.ToInt32(tokens_len[1]);
            LenaSortComparisons(len, c);
        }
    }
}