#include<bits/stdc++.h>
using namespace std; 
#define ll long long int
#define dbl double
#define si set<int>
#define vi vector<int>
#define vii vector<string>
#define mii map<int,int>
#define pii pair<int,int>
#define pll pair<ll,ll>
#define pff pair<double,double>
#define fr(i,n) for(int i=0;i<n;i++)
#define mxx 100001
#define mmm 201
#define mymod 1000000007
#define pcal 1e-5
int main()
{
    clock_t tstart = clock();
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);
    //cout<<fixed<<setprecision(2);
    int t;
    cin>>t;
    while(t--)
    {
      int n,q;
      cin>>n>>q;
      int arr[n];
      fr(i,n)
      arr[i]=i+1;
      bool flag = true;
      fr(i,q)
      {
        bool f = next_permutation(arr,arr+n);
        if(!f)
        {
          flag = false;
          break;
        }
      }
     /* if(flag)
        fr(i,n)
      cout<<arr[i]<<" ";
      else
        cout<<"-1";
      cout<<"\n";*/
        cout<<"-1\n";
    }
   // cout<<"\n\nTotal Time Taken : "<<(double)(-tstart + clock())/CLOCKS_PER_SEC<<"sec\n\n";
    return 0;
}