Square1001 has seen an electric bulletin board displaying the integer 1. He can perform the following operations A and B to change this value:

* Operation A: The displayed value is doubled.
* Operation B: The displayed value increases by K.



Square1001 needs to perform these operations N times in total. Find the minimum possible value displayed in the board after N operations.

Constraints

* 1 \leq N, K \leq 10
* All input values are integers.

Input

Input is given from Standard Input in the following format:


N
K


Output

Print the minimum possible value displayed in the board after N operations.

Examples

Input

4
3


Output

10


Input

10
10


Output

76
import java.util.*;
public class Main{

  public static void main(String[] args){
      Scanner sc = new Scanner(System.in);
      int n = sc.nextInt();
      int k = sc.nextInt();

      int num = 1;
      for(int i = 0; i < n; i++) {
        num = Math.min(num * 2, num + k);
      }
      System.out.println(num);
  }
}

