#include <bits/stdc++.h>   using namespace std;   using ll = long long;      void solve() {       int n, k;       cin >> n >> k;       if(2 * k + 1 > n) {           cout <<  -1 n ;           return;       }       vector<int> v(n);       int p = n;       for(int i = 1; i < 1 + 2 * k; i += 2)           v[i] = p--;       p = 1;       for(int i = 0; i < n; i++) {           if(v[i])               continue;           v[i] = p++;       }       for(auto &x : v)           cout << x <<    ;       cout <<   n ;   }      int main() {       ios_base::sync_with_stdio(false);       cin.tie(0);          int t;       cin >> t;       while(t--)           solve();       }