#include <bits/stdc++.h>
using namespace std;
 
#define ll long long
#define pi (3.141592653589)
#define mod 1000000007
 
int main(){
    int t;
    cin>>t;
    while(t--){
        int n,p;cin>>n>>p;
        int a[n];
        if((n%2==0 && p>=n/2)||(n%2!=0 && p>n/2)){
            cout<<-1<<endl;
        }else{
            for(int i=0;i<n;i++){
                a[i]=i+1;
            }
            int i=1;
            while(p--){
                swap(a[i],a[i+1]);
                i+=2;
            }
            for(int i=0;i<n;i++) cout<<a[i]<<" ";
            cout<<endl;
        }
    }
    return 0;
}
