#include <bits/stdc++.h>

using namespace std;
vector<int> giveRandom(int n,int len)
    {
    vector<int> generatedValues;
    int i=0;
while(i<len){
  int num = rand() % len+1;
    while(find(generatedValues.begin(),generatedValues.end(),num)!=generatedValues.end())
        num=rand()%len+1;
    generatedValues.push_back(num);
    i++;
}
  
    return generatedValues;
}
int main(){
    int q;
    cin >> q;
    for(int a0 = 0; a0 < q; a0++){
        int len;
        int c;
        cin >> len >> c;
        int max=floor(len*(len+1)/2)+1;
        int avg=floor(len*(log2(len)))+1;
        int min=len;
        
        if (c==min-1)
            {
            
            int mid=(1+len)/2;
            cout<<mid<<" ";
            for(int i=1;i<mid;i++)
                cout<<i<<" ";
            for(int i=mid+1;i<=len;i++)
                cout<<i<<" ";
        }
       else if (c >min && c<=avg)
            {
            vector<int> res=giveRandom(c,len);
           for(int i=0;i<len;i++)
               cout<<res[i]<<" ";
        }
        else if (c>avg && c<=max)
            {
            for(int i=len;i>=1;i--)
                cout<<i<<" ";
        }
        else
            cout<<"-1";
        cout<<"\n";
    }
    return 0;
}