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

    System.out.println(min);

  }
}
