#include<bits/stdc++.h>

using namespace std;

void solve(){
    long long n, k;
    cin >> n >> k;
    vector<long long> v;
    long long i = 1;
    v.push_back(i);
    while(i <= n && k > 0){
        v.push_back(i + 2);
        v.push_back(i + 1);
        i += 2;
        k--;
    }
    if(k != 0 || v.size() > n) cout << "-1\n";
    else{
        for(long long i = 0 ; i < v.size() ; i++){
            cout << v[i] << " ";
        }
        long long j = v.size() + 1;
        while(j <= n) {
            cout << j << " ";
            j++;
        }
        cout << "\n";
    }
    return;
}

int main(){
    long long T;
    cin >> T;
    for(long long t = 0 ; t < T ; t++){
        solve();
    }
    return 0;
}