#include<bits/stdc++.h>   #define int long long   using namespace std;   int32_t main()   {   ios::sync_with_stdio(0);   cin.tie(0);   int t;   cin>>t;   while(t--)       {int n,k;        cin>>n>>k;        int ok=1;        int poss=0;        for(int i=0;i<n-1;i++)           {ok=ok*2;            if(ok>=k){poss=1;break;}           }       if(ok<k){cout<< -1 n ;continue;}       vector<int> v;       k--;       for(int i=0;i<n-1;i++)           {//Should I take i+1            int poss=0;            int z=1;            for(int j=0;j<n-i-2;j++)               {z=z*2;                if(z>k){break;}               }           if(z>k)               {v.push_back(i+1);               }           else               {k-=z;               }           }       v.push_back(n);       int visited[n];       memset(visited,0,sizeof(visited));       for(auto x:v)           {               visited[x-1]=1;               cout<<x<<   ;               for(int i=x-1;i>0;i--)                   {                       if(visited[i-1]==1){break;}                       cout<<i<<   ;                   }           }       cout<<  n ;       }   }      