#include <iostream>
#include <stdlib.h>
#include <string.h>
#include <bits/stdc++.h>
using namespace std;

#define ll long long
int main()
{
    ll t;
    cin>>t;
    while(t--)
    {
        
        ll n,k;
        cin>>n>>k;
       
            if(k > (n-(n/2+1)))
            cout<<"-1";
            else
            {
                ll a[n+1];
                for(ll i=1; i<=n; i++)
                a[i] = i;
                ll c=0;
                for(ll i=2; i<n; i=i+2)
                {
                    if(c==k)
                    break;
                    swap(a[i],a[i+1]);
                    c++;
                    
                }
                for(ll i=1; i<=n; i++)
                cout<<a[i]<<" ";
            }
        
        
        cout<<"\n";
    }
}