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.*;

class Main{           
 
   public static void main(String[] args){
      
      Scanner sc = new Scanner(System.in);
            
      int start = 1;

      int N = sc.nextInt();

      int K = sc.nextInt();
                  
      for(int i = 0;i < N;i++){
         start = Math.min(start*2,start+K);                    
      }      
      
      System.out.println(start);
      
      
                                                
   }   
 }