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