#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, k;
  cin >> n >> k;
  for (int i = 1; i <= k; i++) cout << 2 * i - 1 << " " << 2 * i << " ";
  for (int i = k + 1; i <= n; i++) cout << 2 * i << " " << 2 * i - 1 << " ";
  cout << endl;
  return 0;
}
