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 static java.lang.System.out;
import java.util.Scanner;
import java.util.Arrays;
public class Main{
   public static void main(String[] args){
      Scanner sc = new Scanner(System.in); 
      int n = sc.nextInt();
      int k = sc.nextInt();
      int result = 1; // 
      for(int i = 0; i<n ; i++){
         if(result > k){
            result += k;
         }else{
            result *=2;
         }
      }
      out.println(result);
   } 
}