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 scanner = new Scanner (System.in);
    
    int N = scanner.nextInt();
    int K = scanner.nextInt();
    int sum = 1;
    
    if (K <= 2){
      sum += K*N;
    } else {
      for (int i=0; i<N; i++){
        if (sum<K){
          sum=sum*2;
        } else {
          sum+=K;
        }
      }
    }
  
  	System.out.println(sum);
      
  }
}