#include <iostream>
#include <vector>
#include <cstdio>
#include <sstream>
#include <map>
#include <string>
#include <algorithm>
#include <queue>
#include <cmath>
#include <functional>
#include <set>
#include <ctime>
#include <random>
#include <chrono>
#include <cassert>
#include <tuple>
#include <utility>
using namespace std;

namespace {
  using Integer = long long; //__int128;
  template<class T, class S> istream& operator >> (istream& is, pair<T,S>& p){return is >> p.first >> p.second;}
  template<class T> istream& operator >> (istream& is, vector<T>& vec){for(T& val: vec) is >> val; return is;}
  template<class T> istream& operator ,  (istream& is, T& val){ return is >> val;}
  template<class T, class S> ostream& operator << (ostream& os, const pair<T,S>& p){return os << p.first << " " << p.second;}
  template<class T> ostream& operator << (ostream& os, const vector<T>& vec){for(size_t i=0; i<vec.size(); i++) os << vec[i] << (i==vec.size()-1?"":" "); return os;}
  template<class T> ostream& operator ,  (ostream& os, const T& val){ return os << " " << val;}

  //C++14
  // tuple_util::apply( function, result, tuple<args>)
  #include <tuple>
  #include <utility>
  namespace tuple_util{
    template<class F, class R, class ... Args, size_t... I> void apply(F& f, R& res, tuple<Args...>& t, index_sequence<I...>){ res = f( get<I>(t)... ); }
    template<class F, class R, class ... Args> void apply(F& f, R& res, tuple<Args...>& t){ apply(f,res,t, index_sequence_for<Args...>{} ); }
    template<class T, size_t ... I> void input (istream& is, T& t, index_sequence<I...>){ using s=int[]; (void)s{(void(is>>get<I>(t)),0)...} ; }
    template<class T, size_t ... I> void output(ostream& os, T& t, index_sequence<I...>){ using s=int[]; (void)s{(void(os<<get<I>(t)<<" "),0)...} ; }
  }
  template<class... Args> istream& operator >> (istream& is, tuple<Args...>& t){ tuple_util::input (is, t, index_sequence_for<Args...>{}); return is;}
  template<class... Args> ostream& operator << (ostream& os, const tuple<Args...>& t){ tuple_util::output(os, t, index_sequence_for<Args...>{}); return os;}

  template<class H> void print(const H& head){ cout << head; }
  template<class H, class ... T> void print(const H& head, const T& ... tail){ cout << head << " "; print(tail...); }
  template<class ... T> void println(const T& ... values){ print(values...); cout << endl; }

  template<class H> void eprint(const H& head){ cerr << head; }
  template<class H, class ... T> void eprint(const H& head, const T& ... tail){ cerr << head << " "; eprint(tail...); }
  template<class ... T> void eprintln(const T& ... values){ eprint(values...); cerr << endl; }

  class range{ Integer start_, end_, step_; public: struct range_iterator{ Integer val, step_; range_iterator(Integer v, Integer step) : val(v), step_(step) {} Integer operator * (){return val;} void operator ++ (){val += step_;} bool operator != (range_iterator& x){return step_ > 0 ? val < x.val : val > x.val;} }; range(Integer len) : start_(0), end_(len), step_(1) {} range(Integer start, Integer end) : start_(start), end_(end), step_(1) {} range(Integer start, Integer end, Integer step) : start_(start), end_(end), step_(step) {} range_iterator begin(){ return range_iterator(start_, step_); } range_iterator   end(){ return range_iterator(  end_, step_); } };

  inline string operator "" _s (const char* str, size_t size){ return move(string(str)); }
  constexpr Integer my_pow(Integer x, Integer k, Integer z=1){return k==0 ? z : k==1 ? z*x : (k&1) ? my_pow(x*x,k>>1,z*x) : my_pow(x*x,k>>1,z);}
  constexpr Integer my_pow_mod(Integer x, Integer k, Integer M, Integer z=1){return k==0 ? z%M : k==1 ? z*x%M : (k&1) ? my_pow_mod(x*x%M,k>>1,M,z*x%M) : my_pow_mod(x*x%M,k>>1,M,z);}
  constexpr unsigned long long operator "" _ten (unsigned long long value){ return my_pow(10,value); }

  inline int k_bit(Integer x, int k){return (x>>k)&1;} //0-indexed

  mt19937 mt(chrono::duration_cast<chrono::nanoseconds>(chrono::steady_clock::now().time_since_epoch()).count());

  template<class T> string join(const vector<T>& v, const string& sep){ stringstream ss; for(size_t i=0; i<v.size(); i++){ if(i>0) ss << sep; ss << v[i]; } return ss.str(); }

  inline string operator * (string s, int k){ string ret; while(k){ if(k&1) ret += s; s += s; k >>= 1; } return ret; }
}
constexpr long long mod = 9_ten + 7;

int main(){
  long long n, k;
  cin >> n,k;

  if(2*k-1 > n){
    println(-1);
    return 0;
  }

  vector<int> a(n);
  for(int i=0; i<n; i++){
    a[i] = 2*n + i - k;
  }

  vector<int> used(2*n, 0);
  vector<tuple<int,int,int>> b;
  for(int i=0, j=n*2-1; i<2*n; i+=2, j--){
    if(i>=j) break;
    if(i+j > a.back()) break;
    used[i] = 1;
    used[j] = 1;
    b.emplace_back(i+j, i, j);
  }
  for(int i=0, j=2*n-1; i<2*n; i++, j--){
    while(i<2*n-1 && used[i]) i++;
    while(j>i && used[j]) j--;
    if(i<2*n-1 && j>i){
      used[i] = 1;
      used[j] = 1;
      b.emplace_back(i+j, i, j);
    }
  }

  sort(b.begin(), b.end());
  assert(b.size() == n);
  for(int i=0; i<n; i++){
    int x, y, z;
    tie(ignore, x, y) = b[i];
    z = a[i];
    if(x+y > z){
      assert(x+y<=z);
    }

    b[i] = make_tuple(x+k, y+k, z+2*k);
  }

  println(join(b, "\n"));

  return 0;
}


Measured memory_bytes: 9076