package chelper;

import io.InputReader;
import io.OutputWriter;
import solutions.ChelperSolution;


public class TaskB extends ChelperSolution {

  @Override
  public void solve(int testNumber, InputReader in, OutputWriter out) {
    super.solve(testNumber, in, out);
  }

  @Override
  public void solve(int testNumber) {
    int n = in.nextInt();
    int k = in.nextInt() - 1;

    int l = k;
    int r = n - l - 1;

    out.println(n + Math.min(l, r) + n - 1 + n + 1);
  }
}